Replace dependencies+needs with needs+artifacts in GitLabCI config

Replace dependencies+needs with needs+artifacts in GitLabCI config

All jobs now use solely the newer needs configuration to declare
dependencies between jobs:

    needs:
      - job: <foo>
        artifacts: true

instead of combination of dependencies and needs which is deprecated.
This change completely unbundles the stages (alas the stages still needs
to stay because the job graph has to stay acyclic between the stages).

(cherry picked from commit 66ba808c1b69e53427d7f0bb40c7134996ca764a)