Allow empty commits

Author: certik

.github/workflows/deploy.yml

@@ -63,7 +63,7 @@ jobs:
       run: |
         git add .
         COMMIT_MESSAGE="Deploying on $(date "+%Y-%m-%d %H:%M:%S")"
-        git commit -m "${COMMIT_MESSAGE}"
+        git commit --allow-empty -m "${COMMIT_MESSAGE}"
 
     - name: GIT Deploy
       if: ${{ github.ref != 'refs/heads/main' && github.event.pull_request.head.repo.full_name == 'lpython/lpython.org-deploy' }}