Update repo to isort v5 (#6686)

* Run new isort

* More changes

* Update CI, CONTRIBUTING and benchmarks

examples/token-classification/utils_ner.py

@@ -23,7 +23,6 @@ from enum import Enum
 from typing import List, Optional, Union
 
 from filelock import FileLock
-
 from transformers import PreTrainedTokenizer, is_tf_available, is_torch_available