pipeline: fix container image name for dependabot

.github/workflows/container-image.yml

@@ -17,7 +17,8 @@ jobs:
       # https://web.archive.org/web/20250103123053/https://docs.docker.com/build/ci/github-actions/manage-tags-labels/
       uses: docker/metadata-action@v5
       with:
-        images: ghcr.io/${{ github.actor }}/systemctl-mqtt
+        # see comment on `push: true` below
+        images: ghcr.io/${{ github.repository_owner }}/systemctl-mqtt
         # https://web.archive.org/web/20250103130404/https://github.com/docker/metadata-action?tab=readme-ov-file#tags-input
         tags: |
           type=semver,pattern={{version}}
@@ -52,6 +53,10 @@ jobs:
           linux/arm/v6
           linux/arm/v7
           linux/arm64
+        # > Require approval for all external contributors
+        # > All users that are not a member or owner of this repository will
+        # > require approval to run workflows.
+        # https://github.com/fphammerle/systemctl-mqtt/settings/actions
         push: true
         tags: ${{ steps.meta.outputs.tags }}
         labels: ${{ steps.meta.outputs.labels }}