update the latest tag more frequently

as of now, the latest tag on (say) the gitaly image is severely out of date:

root@gitaly-01:~# podman run -it --rm --entrypoint /usr/local/bin/gitaly registry.gitlab.com/gitlab-org/build/cng/gitaly --help
Gitaly, version 13.3.0-rc5
Usage: /usr/local/bin/gitaly [OPTIONS] configfile
  -version
        Print version and exit

that release is years old, and missing a ton of features. it's probably insecure too. it is:

Published to the gitlab-org/build/cng/gitaly image repository on 23 August 2022 at 00:52:12 GMT-4

there's a master tag, but that one is the other way around: it's running bleeding edge:

root@gitaly-01:~# podman run -it --rm -v  /home/git/repositories:/home/git/repositories --entrypoint /usr/local/bin/gitaly registry.gitlab.com/gitlab-org/build/cng-mirror/gitaly:master --version
Gitaly, version 18.1.0-rc1-156-gf7cbbb3e

right now, the best tag one seems to be able to use is 18-1-stable, but that changes every minor release, it seems like:

root@gitaly-01:~# podman run -it --rm -v  /home/git/repositories:/home/git/repositories --entrypoint /usr/local/bin/gitaly registry.gitlab.com/gitlab-org/build/cng-mirror/gitaly:18-1-stable --version
Gitaly, version 18.1.2

i think the latest tag should be dropped, immediately, because it's clearly not the "latest". then let people fix things when they break, because that's better than deploying outdated software.

then it should either be fixed to point to the latest stable release (e.g. 18-1-stable right now) or a new tag (stable?) should be added to point there.

makes sense?

i understand that the helm deployments hardcode version numbers so they're less affected by this, but it seems to me dangerous to leave such old tags lying around anyways, and it would be nice to support users wanting to do simpler deployments on their own.

(this was originally filed against gitaly in gitlab-org/gitaly#6830 (closed) but i figured it belongs here instead)