Use actions/checkout for checkout (#10630)

## Problem
1. First of all it's more correct
2. Current usage allows ` Time-of-Check-Time-of-Use (TOCTOU) 'Pwn
Request' vulnerabilities`. Please check security slack channel or reach
me for more details. I will update PR description after merge.

## Summary of changes
1. Use `actions/checkout` with `ref: ${{
github.event.pull_request.head.sha }}`

Discovered by and Co-author: @varunsh-coder

.github/workflows/approved-for-ci-run.yml

@@ -94,7 +94,9 @@ jobs:
           echo "LABELS_TO_ADD=${LABELS_TO_ADD}" >> ${GITHUB_OUTPUT}
           echo "LABELS_TO_REMOVE=${LABELS_TO_REMOVE}" >> ${GITHUB_OUTPUT}
 
-      - run: gh pr checkout "${PR_NUMBER}"
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
 
       - run: git checkout -b "${BRANCH}"