Less api calls when resolving data_files
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_7805). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.
There ~10 unnecessary `/api/datasets/user/dataset/revision`calls due to multithreading in data files resolution.

I disabled multithreading, which was actually not useful anymore since `HfFileSystem` has been using caching for a while now.