Merge pull request #605 from Cysharp/dependabot/github_actions/peaceiris/actions-gh-pages-4

chore(deps): bump peaceiris/actions-gh-pages from 3 to 4

Author: guitarrapc

.github/workflows/build-docs.yml

@@ -25,7 +25,7 @@ jobs:
         with:
           args: build docs/docfx.json
       - name: Publish to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: docs/_site