Don't retag latest when rebuilding older versions

[svenklemm]

Currently latest will always be retagged unless the version we build for is a beta version. This is undesirable because when we rebuild 2.9.0 it will be tagged as latest even though 2.9.1 is already out and therefore latest should not have been overwritten.
We should also have a test in CI that latest is in fact the latest version to detect this.

[akuzm]

I guess for now I'll just add a toggle to workflow parameters to manually disable tagging, so that we can release the pending fixes without breaking the latest tag again.

[philkra]

@svenklemm is this still an issue?

[svenklemm]

Yes still an issue

[akuzm]

On the good side, I did add a toggle, and we now have some tests that fail if latest is wrong.