Tag auto deploy with Omnibus commit timestamp
We want to tag with something that increments, in order for the package to be SemVer, but not with something that always increments, like the pipeline ID, even when nothing's changed internally.
This way, when we commit changes to Omnibus, whether through VERSION file changes or directly in the project itself, the "last commit" timestamp changes and "updates" the tag version.
Closes https://gitlab.com/gitlab-org/release/framework/issues/325
Edited by Robert Speicher