fixed the empty user error

.forgejo/workflows/container-build.yml

@@ -16,7 +16,7 @@ jobs:
         env:
           REGISTRY_AUTH_FILE: ${{env.RUNNER_TEMP}}/auth.json
         run: |
-          skopeo login -u '' -p ${GITHUB_TOKEN} ${GITHUB_SERVER_URL}
+          skopeo login -u 'user' -p ${GITHUB_TOKEN} ${GITHUB_SERVER_URL}
           skopeo copy -a --dest-precompute-digests containers-storage:localhost/keycloak:latest ${GITHUB_SERVER_URL//https:/docker:}/${{ env.GITHUB_REPOSITORY }}:latest
       - name: Cleanup
         run: |