fix(ci): add MIT license and required Zot annotations

.gitea/workflows/publish-docker.yml

@@ -14,15 +14,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Log in to Gitea Container Registry
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Zot Container Registry
         uses: docker/login-action@v3
         with:
           registry: registry.br0tkasten.de
           username: runner
-          # access token of the user triggering this action
-          # in gitea -> user settings -> applications -> new token -> write:packages and write:repositories
-          # then in gitea -> user settings -> actions -> secrets -> add new secret named "TOKEN" with the value of the access token.
-          password: ${{ secrets.TOKEN }} 
+          # Zot credentials for runner, stored in the Gitea Actions secret TOKEN.
+          password: ${{ secrets.TOKEN }}
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
@@ -40,8 +41,11 @@ jobs:
         uses: docker/build-push-action@v5
         with:
           context: .
-          push: true
-          # Compatibility workaround for registry manifest rejection with attestations.
+          outputs: type=registry,oci-mediatypes=true
+          # Keep a single image manifest with the annotations required by Zot's linter.
           provenance: false
+          annotations: |
+            manifest:org.opencontainers.image.vendor=br0tkasten.de
+            manifest:org.opencontainers.image.licenses=MIT
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}