Upgrade GitHub Pages action to version 4

Author: robotastic

.github/workflows/deploy.yml

@@ -26,9 +26,9 @@ jobs:
       # Popular action to deploy to GitHub Pages:
       # Docs: https://github.com/peaceiris/actions-gh-pages#%EF%B8%8F-docusaurus
       - name: Deploy to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         with:
-          deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
+          deploy_key: ${{ secrets.GITHUB_TOKEN }}
           # Build output to publish to the `gh-pages` branch:
           publish_dir: ./build
           # The following lines assign commit authorship to the official
@@ -37,4 +37,4 @@ jobs:
           # The GH actions bot is used by default if you didn't specify the two fields.
           # You can swap them out with your own user credentials.
           user_name: github-actions[bot]
-          user_email: 41898282+github-actions[bot]@users.noreply.github.com
+          user_email: 41898282+github-actions[bot]@users.noreply.github.com