⚠️ CI failed on Wheel builder ⚠️

**CI failed on [Wheel builder](https://github.com/scikit-learn/scikit-learn/actions/runs/5274563578)** (Jun 15, 2023)

COMMENT:
Looks like `test_learning_curve_display_deprecate_log_scale `is missing a marker to say "skip if matplotlib is not installed". Weird that it was not seen before merging, we should have a CI build without matplotlib in principle, right?

Traceback:
```
_______________ test_learning_curve_display_deprecate_log_scale ________________

caller_name = 'LearningCurveDisplay.from_estimator'

    def check_matplotlib_support(caller_name):
        """Raise ImportError with detailed error message if mpl is not installed.
    
        Plot utilities like any of the Display's plotting functions should lazily import
        matplotlib and call this helper before any computation.
    
        Parameters
        ----------
        caller_name : str
            The name of the caller that requires matplotlib.
        """
        try:
>           import matplotlib  # noqa
E           ModuleNotFoundError: No module named 'matplotlib'

../venv-test/lib/python3.10/site-packages/sklearn/utils/__init__.py:1171: ModuleNotFoundError

The above exception was the direct cause of the following exception:

data = [array([[5.8, 2.8, 5.1, 2.4],
       [6. , 2.2, 4. , 1. ],
       [5.5, 4.2, 1.4, 0.2],
       [7.3, 2.9, 6.3, 1.8],
 ...0, 2, 1, 2, 1, 0, 2, 0, 2, 0, 0, 2, 0, 2, 1, 1, 1, 2, 2,
       1, 1, 0, 1, 2, 2, 0, 1, 1, 1, 1, 0, 0, 0, 2, 1, 2, 0])]

    def test_learning_curve_display_deprecate_log_scale(data):
        """Check that we warn for the deprecated parameter `log_scale`."""
        X, y = data
        estimator = DecisionTreeClassifier(random_state=0)
    
        with pytest.warns(FutureWarning, match="`log_scale` parameter is deprecated"):
>           display = LearningCurveDisplay.from_estimator(
                estimator, X, y, train_sizes=[0.3, 0.6, 0.9], log_scale=True
            )

../venv-test/lib/python3.10/site-packages/sklearn/model_selection/tests/test_plot.py:534: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
../venv-test/lib/python3.10/site-packages/sklearn/model_selection/_plot.py:495: in from_estimator
    check_matplotlib_support(f"{cls.__name__}.from_estimator")
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

caller_name = 'LearningCurveDisplay.from_estimator'

    def check_matplotlib_support(caller_name):
        """Raise ImportError with detailed error message if mpl is not installed.
    
        Plot utilities like any of the Display's plotting functions should lazily import
        matplotlib and call this helper before any computation.
    
        Parameters
        ----------
        caller_name : str
            The name of the caller that requires matplotlib.
        """
        try:
            import matplotlib  # noqa
        except ImportError as e:
>           raise ImportError(
                "{} requires matplotlib. You can install matplotlib with "
                "`pip install matplotlib`".format(caller_name)
            ) from e
E           ImportError: LearningCurveDisplay.from_estimator requires matplotlib. You can install matplotlib with `pip install matplotlib`

../venv-test/lib/python3.10/site-packages/sklearn/utils/__init__.py:1173: ImportError
```

Labels: Bug