Remove misc workarounds, split/rework release stage
While looking at the recent breakage of the releasing stages - mea culpa - I noticed some related and somewhat related gotchas.
The series builds on top of the multilib-devel MR from earlier and it:
- removes some misleading before_script instance in the image template
- removes no longer needed bot workaround
- omits fetching the unneeded tarballs, for publish-dockerhub
- renames the tarballs/sha256 to have BUILD_VERSION suffix and consistently uses the rootfs_file variable
- removes the ci/get-public-download-for-generic-package.sh workaround, since PACKAGE_REGISTRY_URL works
- splits the current release stage - prep vs release vs docker website handling (last one is moved to publish-dockerhub)
The series is semi-tested by dropping the restrictive only/secure stansa - gitlab releasing went fine. Github one is untested.
The next piece (after finishing the pending MRs) will be adding a shellcheck linter stage and fleshing out the final two shell blobs (pre-release and publish-dockerhub) into standalone scripts. Although I suspect that'll take a few weeks to materialise.