Bump JamesIves/github-pages-deploy-action from 4.6.4 to 4.6.8

Bumps [JamesIves/github-pages-deploy-action](https://github.com/jamesives/github-pages-deploy-action) from 4.6.4 to 4.6.8.
- [Release notes](https://github.com/jamesives/github-pages-deploy-action/releases)
- [Commits](JamesIves/github-pages-deploy-action@v4.6.4...v4.6.8)

---
updated-dependencies:
- dependency-name: JamesIves/github-pages-deploy-action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/test_doc.yml

@@ -73,7 +73,7 @@ jobs:
           touch _build/html/.nojekyll
 
       - name: Deploy Github Pages 🚀
-        uses: JamesIves/[email protected].4
+        uses: JamesIves/[email protected].8
         with:
           branch: gh-pages
           folder: docs/_build/html/