Add comment clarifying Python setup purpose

Co-authored-by: jmiller-moko <230051081+jmiller-moko@users.noreply.github.com>

.github/workflows/deploy_staging.yml

@@ -57,6 +57,7 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.x'
+        # Python is required for validation scripts
 
       - name: Run pre-deployment validations
         run: |