Bump peaceiris/actions-gh-pages from 3.8.0 to 3.9.2 (#25)

Bumps [peaceiris/actions-gh-pages](https://github.com/peaceiris/actions-gh-pages) from 3.8.0 to 3.9.2.
- [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@v3.8.0...v3.9.2)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Nicholas Smith <nick.smith@cern.ch>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -31,7 +31,7 @@ jobs:
           touch build/html/.nojekyll
 
       - name: Deploy documentation
-        uses: peaceiris/actions-gh-pages@v3.8.0
+        uses: peaceiris/actions-gh-pages@v3.9.2
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./docs/build/html