Add Gemini PR reviewer to GitHub workflows (#7507)

Author: enkeefe00

.github/workflows/code-review.yml

@@ -0,0 +1,21 @@
+name: Gemini Code Review
+
+on:
+  pull_request_target:
+    types: [opened, synchronize] # Only run on pull requests that are opened or updated
+
+jobs:
+  review:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+      id-token: write
+    steps:
+      - name: Checkout pull request branch
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }} # Use the head SHA of the pull request
+      - uses: sshnaidm/gemini-code-review-action@v1
+        with:
+          gemini-key: ${{ secrets.GEMINI_API_KEY }}