chore: add PR title linter (#5416)

.github/workflows/pr_lint.yml

@@ -0,0 +1,43 @@
+name: PR Title Lint
+
+permissions:
+  pull-requests: read
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize]
+
+jobs:
+  lint-pr-title:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Validate PR Title
+        uses: amannn/action-semantic-pull-request@v5
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          types: |
+            feat
+            fix
+            docs
+            style
+            refactor
+            perf
+            test
+            build
+            ci
+            chore
+            revert
+            release
+          scopes: |
+            checkpoint
+            checkpoint-postgres
+            checkpoint-sqlite
+            cli
+            langgraph
+            prebuilt
+            scheduler-kafka
+            sdk-py
+          requireScope: false
+          ignoreLabels: |
+            ignore-lint-pr-title