fix(deps): update dependency google-protobuf to v4

Author: renovate-bot

mock-server/package.json

@@ -4,7 +4,7 @@
   "dependencies": {
     "@grpc/proto-loader": "^0.5.0",
     "async": "^1.5.2",
-    "google-protobuf": "^3.0.0",
+    "google-protobuf": "^4.0.0",
     "@grpc/grpc-js": "^1.1.0",
     "lodash": "^4.6.1",
     "minimist": "^1.2.0"