Convert_to_parquet fails for datasets with multiple configs
Many users have encountered the same issue, which has caused inconvenience.

https://discuss.huggingface.co/t/convert-to-parquet-fails-for-datasets-with-multiple-configs/86733
 Thanks for reporting.

I will make the code more robust. I have opened an issue in the huggingface-hub repo:
- https://github.com/huggingface/huggingface_hub/issues/2419

I am opening a PR to avoid calling `create_branch` if the branch already exists.
If the dataset has multiple configs, when using the `datasets-cli convert_to_parquet` command to avoid issues with the data viewer caused by loading scripts, the conversion process only successfully converts the data corresponding to the first config. When it starts converting the second config, it throws an error:

```
Traceback (most recent call last):
  File "/opt/anaconda3/envs/dl/bin/datasets-cli", line 8, in <module>
    sys.exit(main())
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/datasets/commands/datasets_cli.py", line 41, in main
    service.run()
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/datasets/commands/convert_to_parquet.py", line 83, in run
    dataset.push_to_hub(
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/datasets/dataset_dict.py", line 1713, in push_to_hub
    api.create_branch(repo_id, branch=revision, token=token, repo_type="dataset", exist_ok=True)
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/huggingface_hub/utils/_validators.py", line 114, in _inner_fn
    return fn(*args, **kwargs)
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/huggingface_hub/hf_api.py", line 5503, in create_branch
    hf_raise_for_status(response)
  File "/opt/anaconda3/envs/dl/lib/python3.10/site-packages/huggingface_hub/utils/_errors.py", line 358, in hf_raise_for_status
    raise BadRequestError(message, response=response) from e
huggingface_hub.utils._errors.BadRequestError:  (Request ID: Root=1-669fc665-7c2e80d75f4337496ee95402;731fcdc7-0950-4eec-99cf-ce047b8d003f)

Bad request:
Invalid reference for a branch: refs/pr/1
```