Make filename matching more robust
_The documentation is not available anymore as the PR was closed or merged._ > I think we should also modify one of the metadata files in the `folder_based_builder` tests to make sure "./" is ignored now in the `file_name`

@mariosasko what do you mean here? I'm not sure which metadata file I should modify here You can modify this line for instance: https://github.com/huggingface/datasets/blob/2699593b33ee63d17aad2a2bfddedd38a8df57b8/tests/packaged_modules/test_folder_based_builder.py#L135
Fix  #5046