@Ta180m workflow

The repository has several branches: * main corresponds to [PR #20391]. Development mainly happens on this branch. * feature-activitypub corresponds to PR #19133 which has been merged. All the other branches mostly contain some experimental or old code and aren't important. To deploy to my testing instance at https://test.exozy.me, I run TAGS="sqlite sqlite_unlock_notify" make watch. For my other testing instance at https://git.exozy.me, I run TAGS="bindata" make && sudo systemctl stop gitea && sudo cp gitea /usr/bin/gitea && sudo systemctl start gitea.