upload_folder (more broadly create_commit) should not reupload LFS files that are already uploaded

[Wauplin]

Related to #1352. I'm creating this issue to decouple this problem from the initial topic (the push(...) method).

At the moment, if a user creates a commit (with upload_file, upload_folder or create_commit) to add an LFS file to the repo, the file will be uploaded to S3, no matter if it already exists there or not.

EDIT: don't know why I ended up thinking it was the case. LFS files are never re-uploaded and that's nice!

huggingface_hub/src/huggingface_hub/_commit_api.py

Line 310 in 32c438f

# Step 2: ignore files that have already been uploaded

.