Add all org.opencontainers.image.xxx labels using --label instead of LABEL

.github/workflows/docker.yml

@@ -42,6 +42,10 @@ jobs:
           type=ref,suffix=-{{sha}},event=branch
           type=ref,event=tag
           type=ref,suffix=-{{sha}},event=tag
+        # The rest of the org.opencontainers.image.xxx labels are dynamically generated
+        labels: |
+          org.opencontainers.image.description=SnappyMail
+          org.opencontainers.image.licenses=AGPLv3
 
     # See: https://github.com/docker/build-push-action/blob/v2.6.1/docs/advanced/cache.md#github-cache
     - name: Set up QEMU
@@ -83,6 +87,7 @@ jobs:
         platforms: linux/386,linux/amd64
         push: true
         tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}
         cache-from: type=local,src=/tmp/.buildx-cache
         cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max