ValueError when running BeamBasedBuilder with GCS path in cache_dir
The cause of the error seems to be that `datasets` adds "gcs://" as a schema, while `beam` checks only "gs://".

datasets: https://github.com/huggingface/datasets/blob/c02a44715c036b5261686669727394b1308a3a4b/src/datasets/builder.py#L822

beam: [link](https://github.com/apache/beam/blob/25e1a64641b1c8a3c0a6c75c6e86031b87307f22/sdks/python/apache_beam/io/filesystems.py#L98-L101)
```
      systems = [
          fs for fs in FileSystem.get_all_subclasses()
          if fs.scheme() == path_scheme
      ]
```
### Describe the bug

When running the BeamBasedBuilder with a GCS path specified in the cache_dir, the following ValueError occurs:

```
ValueError: Unable to get filesystem from specified path, please use the correct path or ensure the required dependency is installed, e.g., pip install apache-beam[gcp]. Path specified: gcs://my-bucket/huggingface_datasets/my_beam_dataset/default/0.0.0/my_beam_dataset-train [while running 'train/Save to parquet/Write/WriteImpl/InitializeWrite']
```

Same error occurs after running `pip install apache-beam[gcp]` as instructed.

### Steps to reproduce the bug

Put `my_beam_dataset.py`:

```python
import datasets


class MyBeamDataset(datasets.BeamBasedBuilder):
    def _info(self):
        features = datasets.Features({"value": datasets.Value("int64")})
        return datasets.DatasetInfo(features=features)

    def _split_generators(self, dl_manager, pipeline):
        return [datasets.SplitGenerator(name=datasets.Split.TRAIN, gen_kwargs={})]

    def _build_pcollection(self, pipeline):
        import apache_beam as beam

        return pipeline | beam.Create([{"value": i} for i in range(10)])
```

Run:
```bash
datasets-cli run_beam my_beam_dataset.py --cache_dir=gs://my-bucket/huggingface_datasets/ --beam_pipeline_options="runner=DirectRunner"
```

### Expected behavior

Running the BeamBasedBuilder with a GCS cache path without any errors.

### Environment info

- `datasets` version: 2.14.4
- Platform: macOS-13.4-arm64-arm-64bit
- Python version: 3.9.17
- Huggingface_hub version: 0.16.4
- PyArrow version: 9.0.0
- Pandas version: 2.0.3