Support huggingface-hub 0.20.0

[albertvillanova]

CI to test the support of huggingface-hub 0.20.0: main...ci-test-huggingface-hub-v0.20.0.rc1

We need to merge:

• Replace list_files_info with list_repo_tree in push_to_hub #6510
• Remove deprecated HfFolder #6512
• Support huggingface-hub pre-releases #6516