Update datasets to 2.19.1
Update datasets to 2.19.1: https://github.com/huggingface/datasets/releases/tag/2.19.1

> Bug fixes
> - Fix download for dict of dicts of URLs by @albertvillanova in https://github.com/huggingface/datasets/pull/6871
Update datasets to 2.19.1: Update datasets to 2.19.1: https://github.com/huggingface/datasets/releases/tag/2.19.1

> Bug fixes
> - Fix download for dict of dicts of URLs by @albertvillanova in https://github.com/huggingface/datasets/pull/6871