update workflow

Author: ohmayr

.github/workflows/unittest.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        option: ["", "_grpc_gcp", "_wo_grpc", "_w_prerelease_deps", "_w_async_rest_extra"]
+        option: ["", "_wo_grpc", "_w_prerelease_deps", "_w_async_rest_extra"]
         python:
           - "3.7"
           - "3.8"