fix(ci): build and push the images for release tags

Pushing a release tag built no images, so data-lab-api:0.1.0 and data-lab-admin-ui:0.1.0, which the helm chart uses, don't exist.

build-and-push now also runs for tags like 0.1.0 and names both images after the tag. Branch builds keep their ci-<branch>-<sha> and <branch> names.

After merging, move the 0.1.0 tag to the merge commit on main and push it.