GitHub now holds a push mirror of this repository. The org variable
BUILD_ON picks which forge builds: set to 'github', the test and release
jobs run in .github/workflows/ci.yml on GitHub's runners, attach the
archives to the Gitea Release, and report back as the commit status
"github/ci (branch)" or "github/ci (tag)". Gitea's ci.yml skips its own
test and release jobs and waits on that status instead, so its run still
passes or fails with the real result, and it announces the release once
GitHub reports success. Unset, nothing changes: Gitea builds as before.
The GitHub-era release workflow is replaced by ci.yml.
The end-to-end test moves into ci.yml as a job run by hand: GitHub's
runners are the throwaway VMs it needs, and its weekly schedule is dropped
because schedules belong to Gitea.