Update `dataset_infos.json` with new split info in `Dataset.push_to_hub` to avoid verification error
_The documentation is not available anymore as the PR was closed or merged._
Update `dataset_infos.json` when pushing splits one by one via `Dataset.push_to_hub` to avoid the splits verification error. 

TODO:
~~- [ ] handle token + `{Audio, Image}.embed_storage`~~
- [x] tests