Update files from the datasets library (from 1.5.0)

Release notes: https://github.com/huggingface/datasets/releases/tag/1.5.0

mnist.py

@@ -77,8 +77,6 @@ class MNIST(datasets.GeneratorBasedBuilder):
     def _split_generators(self, dl_manager):
         urls_to_download = {key: _URL + fname for key, fname in _URLS.items()}
         downloaded_files = dl_manager.download_and_extract(urls_to_download)
-        print(downloaded_files)
-
         return [
             datasets.SplitGenerator(
                 name=datasets.Split.TRAIN,