ci(gitlab-ci): Add latest-per-branch tag for images

This patch pushes the branch reference to the container image tags and
also a semi "latest" tag for each branch, which should help
testing/trying new images.

images/.utils/gitlab-ci.yaml

@@ -46,10 +46,11 @@ container-build-dev:
       --label "org.opencontainers.image.created=$(date --rfc-3339 ns)" \
       --label "org.opencontainers.image.title=${IMAGE}" \
       --label "quay.expires-after=12w" \
-      -t "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_SHORT_SHA}" \
+      -t "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_REF_SLUG}-${CI_COMMIT_SHORT_SHA}" \
       --format docker \
       .
-    - podman push "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_SHORT_SHA}"
+    - podman push "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_REF_SLUG}-${CI_COMMIT_SHORT_SHA}"
+    - podman push "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_REF_SLUG}-${CI_COMMIT_SHORT_SHA}" "quay.io/shivering-isles/${IMAGE}:${CI_COMMIT_REF_SLUG}"
   rules:
     - if: '$CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH && $CI_PIPELINE_SOURCE == "push"'
       changes: