This work by automatically pushing a new tag on main and release
branches after each commit. The tag will be "devel" on main and the
version from postgrest.cabal for release branches. The release
workflow then runs as a tag pipeline, making the actual release.
For release branches, the tag will only be created if a tag for this
version doesn't exist, yet. This means to actually make a new patch
release, we still need to bump the version in postgrest.cabal. We
can automate this later as part of our backport-bot.
Resolves#2006Resolves#2997
