Update gh-pages.yml

Author: eksrha

.github/workflows/gh-pages.yml

@@ -27,6 +27,7 @@ jobs:
 
       - name: Deploy
         uses: peaceiris/actions-gh-pages@v3
+        if: github.event_name != 'pull_request'
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./public