ci: updated github checkout version

Author: voorepreethi

.github/workflows/pull_request.yaml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install AWS SAM CLI
         run: |