Merge pull request #226 from ruby-syntax-tree/dependabot/github_actions/peaceiris/actions-gh-pages-4

Bump peaceiris/actions-gh-pages from 3 to 4

Author: github-actions[bot]

.github/workflows/gh-pages.yml

@@ -21,7 +21,7 @@ jobs:
         run: bin/doc
 
       - name: Deploy 🚀
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./doc