Dataset.push_to_hub of a canonical dataset creates an additional dataset under the user namespace
While using `Dataset.push_to_hub` of a canonical dataset, an additional dataset was created under my user namespace.

## Steps to reproduce the bug
The command:
```python
commit_info = ds.push_to_hub(
    "caner",
    config_name="default",
    commit_message="Convert dataset to Parquet",
    commit_description="Convert dataset to Parquet.",
    create_pr=True,
    token=token,
)
```
creates the additional dataset `albertvillanova/caner`.