build: CI check to verify that the protobuf stubs are up-to-date

.circleci/config.yml

@@ -44,6 +44,13 @@ jobs:
             git diff --quiet && exit 0
             echo "please run 'go mod tidy' to ensure go.mod and go.sum are up to date"
             exit 1
+      - run:
+          name: verify that our protobuf stubs are up-to-date
+          command: |
+            make protobuf
+            git diff --quiet && exit 0
+            echo "Run 'make protobuf' to ensure that the protobuf stubs are up-to-date."
+            exit 1
 
   go-test:
     executor: