Version 3 of upload-artifact GH Action is deprecated

[albertvillanova]

The GitHub Action upload-artifact@v3 is deprecated and will raise an error on November 30, 2024: https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

Starting November 30, 2024, GitHub Actions customers will no longer be able to use v3 of actions/upload-artifact or actions/download-artifact. Customers should update workflows to begin using v4 of the artifact actions as soon as possible.

This action is used by build_pr_documentation and it raises a deprecation warning: https://github.com/huggingface/transformers/actions/runs/10809997584

Deprecation notice: v1, v2, and v3 of the artifact actions The following artifacts were uploaded using a version of actions/upload-artifact that is scheduled for deprecation: "doc-build-artifact". Please update your workflow to use v4 of the artifact actions. Learn more: https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/