Bump peaceiris/actions-gh-pages from 3.9.3 to 4.0.0

Bumps [peaceiris/actions-gh-pages](https://github.com/peaceiris/actions-gh-pages) from 3.9.3 to 4.0.0.
- [Release notes](https://github.com/peaceiris/actions-gh-pages/releases)
- [Changelog](https://github.com/peaceiris/actions-gh-pages/blob/main/CHANGELOG.md)
- [Commits](peaceiris/actions-gh-pages@v3.9.3...v4.0.0)

---
updated-dependencies:
- dependency-name: peaceiris/actions-gh-pages
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/deploy.yml

@@ -46,7 +46,7 @@ jobs:
         jupyter-book build .
 
     - name: GitHub Pages action
-      uses: peaceiris/actions-gh-pages@v3.9.3
+      uses: peaceiris/actions-gh-pages@v4.0.0
       if: ${{ github.event_name != 'pull_request' }}
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}