gitlab-ci: Organize images using new REPO_SUFFIX templates feature
Two benefits:
Most docker image related environment variables can now be defined in the jobs where they're used instead of globally. The DEBIAN_TAG values are propagated to other jobs via YAML anchors.
Images on https://gitlab.freedesktop.org/mesa/mesa/container_registry are now organized in separate repositories with a suffix matching the name of the job which makes sure the image is there.
Edited by Michel Dänzer