ci: fix error when PR from fork

.github/workflows/ci_cd.yml

@@ -16,13 +16,17 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
+        with:
+          fetch-depth: 2  # Fetch at least 2 commits to ensure we get non-merge commits
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
           python-version: '3.x'
       - name: Validate commit messages
         run: |
-          git log --pretty=format:"%s" | head -n 1 | python .github/scripts/validate_commit_msg.py
+          # Get the last non-merge commit and validate the message
+          git log --pretty=format:"%s" --no-merges -n 1 | python .github/scripts/validate_commit_msg.py
+
 
   lint:
     runs-on: ubuntu-latest