fix: vulnerability fix use commit hash instead of version

Author: ritikrajdev

.github/workflows/two-step-pr-approval.yml

@@ -14,7 +14,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       - name: Two stage PR review
         uses: hashicorp/[email protected]