ColumnTransformer throws error with n_jobs > 1 input dataframes and joblib auto-memmapping (regression in 1.4.1.post1)

### Describe the bug

Hi,

I have been trying to build a ColumnTransformer with different values in the n_jobs' parameter, but when fitting and transforming throws the error ValueError: cannot set WRITEABLE flag to True of this array. I am fitting directly a Pandas DataFrame, so not sure if that would be the problem.

Thanks

Best

### Steps/Code to Reproduce

```py
from sklearn.preprocessing import (
    PowerTransformer,
    QuantileTransformer,
    MinMaxScaler,
)
from sklearn.pipeline import Pipeline
from sklearn.compose import ColumnTransformer

pow_scaler = PowerTransformer()
quant_scaler = QuantileTransformer(output_distribution="normal")
minmax_scaler = MinMaxScaler()

pip_pow_max = Pipeline(steps=[("pow", pow_scaler), ("max", minmax_scaler)])
pip_quant_max = Pipeline(steps=[("quant", quant_scaler), ("max", minmax_scaler)])

preprocessor = ColumnTransformer(
    transformers=[
        (
            "pip_quant_max",
            pip_quant_max,
            [
                "Length",
                "Diameter",
                "Whole weight",
                "Whole weight.1",
                "Whole weight.2",
                "Shell weight",
            ],
        ),
        ("pip_power_max", pip_pow_max, ["Height"]),
    ],
    remainder="passthrough",
    verbose_feature_names_out=False,
    n_jobs=-1
)

check = pd.DataFrame(
    data=preprocessor.fit_transform(df_train),
    columns=preprocessor.get_feature_names_out(),
)
```

### Expected Results

No error thrown

### Actual Results

```
{
	"name": "ValueError",
	"message": "cannot set WRITEABLE flag to True of this array",
	"stack": "---------------------------------------------------------------------------
_RemoteTraceback                          Traceback (most recent call last)
_RemoteTraceback: 
\"\"\"
Traceback (most recent call last):
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/joblib/externals/loky/process_executor.py\", line 463, in _process_worker
    r = call_item()
        ^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/joblib/externals/loky/process_executor.py\", line 291, in __call__
    return self.fn(*self.args, **self.kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py\", line 589, in __call__
    return [func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py\", line 589, in <listcomp>
    return [func(*args, **kwargs)
            ^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/utils/parallel.py\", line 129, in __call__
    return self.function(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/pipeline.py\", line 1303, in _fit_transform_one
    res = transformer.fit_transform(X, y, **params.get(\"fit_transform\", {}))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/base.py\", line 1474, in wrapper
    return fit_method(estimator, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/pipeline.py\", line 535, in fit_transform
    Xt = self._fit(X, y, routed_params)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/pipeline.py\", line 408, in _fit
    X, fitted_transformer = fit_transform_one_cached(
                            ^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/joblib/memory.py\", line 353, in __call__
    return self.func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/pipeline.py\", line 1303, in _fit_transform_one
    res = transformer.fit_transform(X, y, **params.get(\"fit_transform\", {}))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/utils/_set_output.py\", line 295, in wrapped
    data_to_wrap = f(self, X, *args, **kwargs)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/base.py\", line 1098, in fit_transform
    return self.fit(X, **fit_params).transform(X)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/base.py\", line 1474, in wrapper
    return fit_method(estimator, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/preprocessing/_data.py\", line 2758, in fit
    X = self._check_inputs(X, in_fit=True, copy=False)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/preprocessing/_data.py\", line 2847, in _check_inputs
    X = self._validate_data(
        ^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/base.py\", line 633, in _validate_data
    out = check_array(X, input_name=\"X\", **check_params)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/Users/xxxx/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/utils/validation.py\", line 1097, in check_array
    array.flags.writeable = True
    ^^^^^^^^^^^^^^^^^^^^^
ValueError: cannot set WRITEABLE flag to True of this array
\"\"\"

The above exception was the direct cause of the following exception:

ValueError                                Traceback (most recent call last)
Cell In[31], line 2
      1 check = pd.DataFrame(
----> 2     data=preprocessor.fit_transform(df_train),
      3     columns=preprocessor.get_feature_names_out(),
      4 )
      6 check

File ~/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/utils/_set_output.py:295, in _wrap_method_output.<locals>.wrapped(self, X, *args, **kwargs)
    293 @wraps(f)
    294 def wrapped(self, X, *args, **kwargs):
--> 295     data_to_wrap = f(self, X, *args, **kwargs)
    296     if isinstance(data_to_wrap, tuple):
    297         # only wrap the first output for cross decomposition
    298         return_tuple = (
    299             _wrap_data_with_container(method, data_to_wrap[0], X, self),
    300             *data_to_wrap[1:],
    301         )

File ~/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/base.py:1474, in _fit_context.<locals>.decorator.<locals>.wrapper(estimator, *args, **kwargs)
   1467     estimator._validate_params()
   1469 with config_context(
   1470     skip_parameter_validation=(
   1471         prefer_skip_nested_validation or global_skip_validation
   1472     )
   1473 ):
-> 1474     return fit_method(estimator, *args, **kwargs)

File ~/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/compose/_column_transformer.py:914, in ColumnTransformer.fit_transform(self, X, y, **params)
    911 else:
    912     routed_params = self._get_empty_routing()
--> 914 result = self._call_func_on_transformers(
    915     X,
    916     y,
    917     _fit_transform_one,
    918     column_as_labels=False,
    919     routed_params=routed_params,
    920 )
    922 if not result:
    923     self._update_fitted_transformers([])

File ~/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/compose/_column_transformer.py:823, in ColumnTransformer._call_func_on_transformers(self, X, y, func, column_as_labels, routed_params)
    811             extra_args = {}
    812         jobs.append(
    813             delayed(func)(
    814                 transformer=clone(trans) if not fitted else trans,
   (...)
    820             )
    821         )
--> 823     return Parallel(n_jobs=self.n_jobs)(jobs)
    825 except ValueError as e:
    826     if \"Expected 2D array, got 1D array instead\" in str(e):

File ~/kaggle_2/new_env/lib/python3.11/site-packages/sklearn/utils/parallel.py:67, in Parallel.__call__(self, iterable)
     62 config = get_config()
     63 iterable_with_config = (
     64     (_with_config(delayed_func, config), args, kwargs)
     65     for delayed_func, args, kwargs in iterable
     66 )
---> 67 return super().__call__(iterable_with_config)

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:1952, in Parallel.__call__(self, iterable)
   1946 # The first item from the output is blank, but it makes the interpreter
   1947 # progress until it enters the Try/Except block of the generator and
   1948 # reach the first `yield` statement. This starts the aynchronous
   1949 # dispatch of the tasks to the workers.
   1950 next(output)
-> 1952 return output if self.return_generator else list(output)

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:1595, in Parallel._get_outputs(self, iterator, pre_dispatch)
   1592     yield
   1594     with self._backend.retrieval_context():
-> 1595         yield from self._retrieve()
   1597 except GeneratorExit:
   1598     # The generator has been garbage collected before being fully
   1599     # consumed. This aborts the remaining tasks if possible and warn
   1600     # the user if necessary.
   1601     self._exception = True

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:1699, in Parallel._retrieve(self)
   1692 while self._wait_retrieval():
   1693 
   1694     # If the callback thread of a worker has signaled that its task
   1695     # triggered an exception, or if the retrieval loop has raised an
   1696     # exception (e.g. `GeneratorExit`), exit the loop and surface the
   1697     # worker traceback.
   1698     if self._aborting:
-> 1699         self._raise_error_fast()
   1700         break
   1702     # If the next job is not ready for retrieval yet, we just wait for
   1703     # async callbacks to progress.

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:1734, in Parallel._raise_error_fast(self)
   1730 # If this error job exists, immediatly raise the error by
   1731 # calling get_result. This job might not exists if abort has been
   1732 # called directly or if the generator is gc'ed.
   1733 if error_job is not None:
-> 1734     error_job.get_result(self.timeout)

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:736, in BatchCompletionCallBack.get_result(self, timeout)
    730 backend = self.parallel._backend
    732 if backend.supports_retrieve_callback:
    733     # We assume that the result has already been retrieved by the
    734     # callback thread, and is stored internally. It's just waiting to
    735     # be returned.
--> 736     return self._return_or_raise()
    738 # For other backends, the main thread needs to run the retrieval step.
    739 try:

File ~/kaggle_2/new_env/lib/python3.11/site-packages/joblib/parallel.py:754, in BatchCompletionCallBack._return_or_raise(self)
    752 try:
    753     if self.status == TASK_ERROR:
--> 754         raise self._result
    755     return self._result
    756 finally:

ValueError: cannot set WRITEABLE flag to True of this array"
}
```

### Versions

```shell
System:
    python: 3.11.6 | packaged by conda-forge | (main, Oct  3 2023, 10:37:07) [Clang 15.0.7 ]
executable: /Users/xxxx/kaggle_2/new_env/bin/python
   machine: macOS-14.4.1-arm64-arm-64bit

Python dependencies:
      sklearn: 1.4.1.post1
          pip: 24.0
   setuptools: 69.2.0
        numpy: 1.23.5
        scipy: 1.12.0
       Cython: 3.0.9
       pandas: 2.1.4
   matplotlib: 3.8.3
       joblib: 1.3.2
threadpoolctl: 3.4.0

Built with OpenMP: True

threadpoolctl info:
       user_api: blas
   internal_api: openblas
    num_threads: 10
         prefix: libopenblas
       filepath: /Users/xxxx/kaggle_2/new_env/lib/libopenblas.0.dylib
        version: 0.3.26
threading_layer: openmp
   architecture: VORTEX

       user_api: openmp
   internal_api: openmp
    num_threads: 10
         prefix: libomp
       filepath: /Users/xxxx/kaggle_2/new_env/lib/libomp.dylib
        version: None
```

COMMENT:
I think this is a regression that we introduced in https://github.com/scikit-learn/scikit-learn/pull/28348

The related code snippet is the following:

https://github.com/scikit-learn/scikit-learn/blob/c1d29ce7fc21690bd69a449c7c3b896e74b76f84/sklearn/utils/validation.py#L1090-L1100

Let's start with why the error is trigger. Looking at https://numpy.org/doc/stable/reference/generated/numpy.chararray.setflags.html, we are probably not in this situation anymore:

> The flag WRITEABLE can only be set to True if the array owns its own memory, or the ultimate owner of the memory exposes a writeable buffer interface, or is a string.

While converting a dataframe to an array (e.g. using `to_numpy`) will return a WRITABLE=False array, it seems that `n_jobs=2` will break the the second condition "the ultimate owner of the memory exposes a writeable buffer interface" since the first and last condition are already not the case with `n_jobs=1`.

I need to think more about finding a bug fix if I find any :).

Labels: Bug, Regression