Add codegen check workflow

Make sure that the generated clients are up to date.

.github/workflows/check-codegen.yml

@@ -0,0 +1,21 @@
+name: Check Codegen
+
+on:
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - '**/*.md'
+
+jobs:
+  check-codegen:
+    runs-on: self-hosted
+    steps:
+      - uses: actions/checkout@v3
+      - name: Run make generate
+        run: make generate
+      - name: Check if there are changes
+        id: changes
+        uses: UnicornGlobal/has-changes-action@v1.0.11
+      - name: Process changes
+        if: steps.changes.outputs.changed == 1
+        run: echo "Please run 'make generate' and commit the generated code."