Dataset viewer issue for *P3*

## Dataset viewer issue for '*P3*'

**Link: https://huggingface.co/datasets/bigscience/P3**

```
Status code:   400
Exception:     SplitsNotFoundError
Message:       The split names could not be parsed from the dataset config.
```
Am I the one who added this dataset ? No


The error is now:

```
Status code:   400
Exception:     Status400Error
Message:       this dataset is not supported for now.
```

We've disabled the dataset viewer for several big datasets like this one. We hope being able to reenable it soon.

The list of splits cannot be obtained. cc @huggingface/datasets 

```
Error code:   SplitsNamesError
Exception:    SplitsNotFoundError
Message:      The split names could not be parsed from the dataset config.
Traceback:    Traceback (most recent call last):
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 354, in get_dataset_config_info
                 for split_generator in builder._split_generators(
               File "/tmp/modules-cache/datasets_modules/datasets/bigscience--P3/12c0badfecad4564ecb8a6f81b5d0559656f269f08b13c59c93283f3a84134ba/P3.py", line 154, in _split_generators
                 data_dir = dl_manager.download_and_extract(_URLs)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/download/streaming_download_manager.py", line 944, in download_and_extract
                 return self.extract(self.download(url_or_urls))
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/download/streaming_download_manager.py", line 907, in extract
                 urlpaths = map_nested(self._extract, path_or_paths, map_tuple=True)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 393, in map_nested
                 mapped = [
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 394, in <listcomp>
                 _single_map_nested((function, obj, types, None, True, None))
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 346, in _single_map_nested
                 return {k: _single_map_nested((function, v, types, None, True, None)) for k, v in pbar}
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 346, in <dictcomp>
                 return {k: _single_map_nested((function, v, types, None, True, None)) for k, v in pbar}
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 346, in _single_map_nested
                 return {k: _single_map_nested((function, v, types, None, True, None)) for k, v in pbar}
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 346, in <dictcomp>
                 return {k: _single_map_nested((function, v, types, None, True, None)) for k, v in pbar}
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/utils/py_utils.py", line 330, in _single_map_nested
                 return function(data_struct)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/download/streaming_download_manager.py", line 912, in _extract
                 protocol = _get_extraction_protocol(urlpath, use_auth_token=self.download_config.use_auth_token)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/download/streaming_download_manager.py", line 402, in _get_extraction_protocol
                 return _get_extraction_protocol_with_magic_number(f)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/download/streaming_download_manager.py", line 367, in _get_extraction_protocol_with_magic_number
                 magic_number = f.read(MAGIC_NUMBER_MAX_LENGTH)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/implementations/http.py", line 574, in read
                 return super().read(length)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/spec.py", line 1575, in read
                 out = self.cache._fetch(self.loc, self.loc + length)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/caching.py", line 377, in _fetch
                 self.cache = self.fetcher(start, bend)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 111, in wrapper
                 return sync(self.loop, func, *args, **kwargs)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 96, in sync
                 raise return_result
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 53, in _runner
                 result[0] = await coro
               File "/src/services/worker/.venv/lib/python3.9/site-packages/fsspec/implementations/http.py", line 616, in async_fetch_range
                 out = await r.read()
               File "/src/services/worker/.venv/lib/python3.9/site-packages/aiohttp/client_reqrep.py", line 1036, in read
                 self._body = await self.content.read()
               File "/src/services/worker/.venv/lib/python3.9/site-packages/aiohttp/streams.py", line 375, in read
                 block = await self.readany()
               File "/src/services/worker/.venv/lib/python3.9/site-packages/aiohttp/streams.py", line 397, in readany
                 await self._wait("readany")
               File "/src/services/worker/.venv/lib/python3.9/site-packages/aiohttp/streams.py", line 304, in _wait
                 await waiter
             aiohttp.client_exceptions.ClientPayloadError: Response payload is not completed
             
             The above exception was the direct cause of the following exception:
             
             Traceback (most recent call last):
               File "/src/services/worker/src/worker/responses/splits.py", line 75, in get_splits_response
                 split_full_names = get_dataset_split_full_names(dataset, hf_token)
               File "/src/services/worker/src/worker/responses/splits.py", line 35, in get_dataset_split_full_names
                 return [
               File "/src/services/worker/src/worker/responses/splits.py", line 38, in <listcomp>
                 for split in get_dataset_split_names(dataset, config, use_auth_token=hf_token)
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 404, in get_dataset_split_names
                 info = get_dataset_config_info(
               File "/src/services/worker/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 359, in get_dataset_config_info
                 raise SplitsNotFoundError("The split names could not be parsed from the dataset config.") from err
             datasets.inspect.SplitsNotFoundError: The split names could not be parsed from the dataset config.
```

Closing in favor of https://huggingface.co/datasets/bigscience/P3/discussions/6 and https://github.com/huggingface/datasets-server/issues/1689