Starting January 30th, 2025, 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.

https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

If you have questions, raise them in this discussion or file a support case.