Bump actions/deploy-pages from 3 to 4

Bumps [actions/deploy-pages](https://github.com/actions/deploy-pages) from 3 to 4.
- [Release notes](https://github.com/actions/deploy-pages/releases)
- [Commits](actions/deploy-pages@v3...v4)

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

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

.github/workflows/docs.yaml

@@ -69,5 +69,5 @@ jobs:
           path: "./book"
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v3
+        uses: actions/deploy-pages@v4
         if: github.event_name != 'pull_request'