[CI] fixed trivial bug

Author: glpatcern

.github/workflows/build-and-publish.yml

@@ -37,7 +37,7 @@ jobs:
           git config user.name "cernbox-bot"
           cp ../grpc-proto/build/*.go .
           git add .
-          done=(git commit -m "Synced to https://github.com/cern-eos/grpc-proto/tree/${{ github.sha }}")
+          done=$(git commit -m "Synced to https://github.com/cern-eos/grpc-proto/tree/${{ github.sha }}")
           if [[ $done -eq 0 ]]; then
             git push origin main
           else