upload/download-artifact@v4 is not supported on Gitea (GHES). Replace
with a direct Gitea API call in gitops-update: look up the tag name
whose commit SHA matches workflow_run.head_sha. Reverts the artifact
upload from build.yaml; no changes to build.yaml logic.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>