fix(ci): update protobuf checkout steps in MacOS workflow

Author: sampajano

.github/workflows/make-plugin-mac-os.yml

@@ -18,6 +18,10 @@ jobs:
     - name: Checkout protobuf code
       run: |
         ./scripts/init_submodules.sh
+        cd ./third_party/protobuf
+        git fetch --tags
+        git checkout v27.1
+        cd ../..
     # Protobuf build instructions from:
     # https://github.com/protocolbuffers/protobuf/blob/master/src/README.md
     - name: Build protobuf (configure & make)