Add GHA to check for differences found in .ok files

Same as in OR

Signed-off-by: Matt Liberty <[email protected]>

.github/workflows/github-actions-are-differences-found.yml

@@ -0,0 +1,20 @@
+name: Check that OK files are up to date
+
+on:
+  pull_request:
+
+jobs:
+  No-Diffs-In-Ok-Files:
+    runs-on: ${{ vars.USE_SELF_HOSTED == 'true' && 'self-hosted' || 'ubuntu-latest' }}
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+      - name: Check ok files
+        run: |
+          set +e
+          grep --include="*.ok" -Rn "Differences found "
+          if [[ "$?" == "0" ]]; then
+            exit 1
+          fi