Bump peaceiris/actions-gh-pages from 3.9.0 to 3.9.1

Bumps [peaceiris/actions-gh-pages](https://github.com/peaceiris/actions-gh-pages) from 3.9.0 to 3.9.1.
- [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@v3.9.0...v3.9.1)

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

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

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -33,7 +33,7 @@ jobs:
 
     - name: Publish
       if: github.event_name == 'push'
-      uses: peaceiris/[email protected].0
+      uses: peaceiris/[email protected].1
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_dir: docs/site/_site