Perform hidden file check on relative data file path
_The documentation is not available anymore as the PR was closed or merged._ I'm aware of this behavior, which is tricky to solve due to fsspec's hidden file handling (see https://github.com/huggingface/datasets/issues/4115#issuecomment-1108819538). I've tested some regex patterns to address this, and they seem to work (will push them on Monday; btw they don't break any of fsspec's tests, so maybe we can contribute this as an enhancement to them). Also, perhaps we should include the files starting with `__`  in the results again (we hadn't had issues with this pattern before). WDYT? I see. Feel free to merge this one if it's good for you btw :)

> Also, perhaps we should include the files starting with __ in the results again (we hadn't had issues with this pattern before)

The point was mainly to ignore `__pycache__` directories for example. Also also for consistency with the iter_files/iter_archive which are already ignoring them Very elegant solution! Feel free to merge if the CI is green after adding the tests. CI failure is unrelated to this PR
Fix #4549 