Add latest tag to docker image

Author: jochenboesmans

.github/workflows/release.yml

@@ -94,7 +94,9 @@ jobs:
       uses: docker/build-push-action@v2
       with:
         push: true
-        tags: ${{ steps.determine-docker-image-vars.outputs.ghcr_tags }}
+        tags: |
+          ${{ steps.determine-docker-image-vars.outputs.ghcr_tags }}
+          ${{ steps.determine-docker-image-vars.outputs.ghcr_latest }}
         context: .
         file: ./runner.Dockerfile
         platforms: linux/amd64,linux/arm64