Add a sentinel job to gate master on

.github/workflows/pull-request.yml

@@ -5,6 +5,32 @@ on:
       - master
 jobs:
 
+  sentinel:
+    name: Sentinel
+    if: github.event_name == 'repository_dispatch' ||
+      github.event.pull_request.head.repo.full_name == github.repository
+    permissions:
+      statuses: write
+    needs:
+    - resourcedocsgen
+    - mktutorial
+    - lint-markdown
+    - lint-scripts
+    - preview
+    runs-on: ubuntu-latest
+    steps:
+    - uses: guibranco/github-status-action-v2@0849440ec82c5fa69b2377725b9b7852a3977e76 # v1.1.13
+      with:
+        authToken: ${{secrets.GITHUB_TOKEN}}
+        # Write an explicit status check called "Sentinel" which will only pass if this code really runs.
+        # This should always be a required check for PRs.
+        context: 'Sentinel'
+        description: 'All required checks passed'
+        state: 'success'
+        # Write to the PR commit SHA if it's available as we don't want the merge commit sha,
+        # otherwise use the current SHA for any other type of build.
+        sha: ${{ github.event.pull_request.head.sha || github.sha }}
+
   resourcedocsgen:
     uses: ./.github/workflows/check-go.yml
     with: