Build(deps): Bump peaceiris/actions-gh-pages in the actions group (#78)

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@373f7f2...4f9cc66)

---
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]>

.github/workflows/keep-alive.yml

@@ -26,7 +26,7 @@ jobs:
         touch _pass/pass.txt
 
     - name: Keep workflow alive
-      uses: peaceiris/actions-gh-pages@373f7f263a76c20808c831209c920827a82a2847 #v3.9.3
+      uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e #v4.0.0
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_branch: keep-alive