ci: Add Conventional Commits GitHub Action (#391)

Google GitHub App will be deprecated

Author: holtskinner

.github/actions/spelling/allow.txt

@@ -9,6 +9,7 @@ agentic
 AGrpc
 aio
 aiomysql
+amannn
 aproject
 ARequest
 ARun

.github/workflows/conventional-commits.yml

@@ -0,0 +1,26 @@
+name: "Conventional Commits"
+
+on:
+  pull_request:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+permissions:
+  contents: read
+
+jobs:
+  main:
+    permissions:
+      pull-requests: read
+      statuses: write
+    name: Validate PR Title
+    runs-on: ubuntu-latest
+    steps:
+      - name: semantic-pull-request
+        uses: amannn/action-semantic-pull-request@v5.5.3
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          validateSingleCommit: false