chore: Re-adds Docker Compose test as disabled job

The compose smoke test needs a Docker daemon, which jobs on the current docker runner do not have. It is kept commented out so it can be re-enabled once such a runner exists.

.forgejo/workflows/images.yml

@@ -42,3 +42,31 @@ jobs:
           --annotation=org.opencontainers.image.revision=${{ forgejo.sha }}
           --annotation=org.opencontainers.image.url=${{ forgejo.server_url }}/${{ forgejo.repository }}
           --annotation=org.opencontainers.image.source=${{ forgejo.server_url }}/${{ forgejo.repository }}
+
+  # Docker Compose smoke test, disabled: the current runner setup cannot execute it.
+  # The `docker` runner runs jobs in a container without access to a Docker daemon
+  # (which is why images are built with kaniko), so neither `docker build` nor
+  # `docker compose` is available. Re-enable this job once a runner with a Docker
+  # daemon exists, and set `runs-on` to its label.
+  #
+  # test-compose:
+  #   name: Test with Docker Compose
+  #   needs: build-container
+  #   runs-on: docker  # needs a runner with a Docker daemon
+  #   steps:
+  #     - name: Checkout source code
+  #       uses: actions/checkout@v7
+  #
+  #     - name: Build images
+  #       run: |
+  #         docker build -f web/Containerfile -t git.hamburg.ccc.de/ccchh/sunders/web:ci web
+  #         docker build -f data_handler/Containerfile -t git.hamburg.ccc.de/ccchh/sunders/data_handler:ci data_handler
+  #
+  #     - name: Update docker-compose.yml image tags
+  #       run: |
+  #         sed -i "s/:latest/:ci/g" docker-compose.yml
+  #
+  #     - name: Start Docker Compose services
+  #       run: |
+  #         docker compose up -d --wait
+  #         docker compose down