use deploy key for pushing to external repo

Author: k4rtik

.github/workflows/main.yml

@@ -25,6 +25,6 @@ jobs:
       - name: Hugo Deploy GitHub Pages
         uses: peaceiris/actions-gh-pages@v4
         with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
+          deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
           external_repository: QuantumPL/bib
           publish_dir: ./public