The test/build-docs jobs target a self-hosted runner (racknerd-mini)
that only exists on the Gitea instance. When GitHub re-runs this same
workflow on the mirror, those jobs sit queued forever with no matching
runner, so the commit never gets a completed status.
Gate both jobs to skip when github.server_url is github.com, and add a
trivial github-mirror job (runs-on: ubuntu-latest, which GitHub does
provide) that only runs on the mirror, so the check completes instead
of hanging.
rootiest