Build(deps): Bump peaceiris/actions-gh-pages in the actions group (#823)

Bumps the actions group with 1 update: [peaceiris/actions-gh-pages](https://github.com/peaceiris/actions-gh-pages).


Updates `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
  dependency-group: actions
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build-docs.yml

@@ -44,7 +44,7 @@ jobs:
           AIRNOW_API: ${{ secrets.AIRNOW_API }}
       # Push the book's HTML to github-pages
       - name: GitHub Pages action
-        uses: peaceiris/actions-gh-pages@v3.9.3
+        uses: peaceiris/actions-gh-pages@v4.0.0
         if: github.ref == 'refs/heads/main'
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}