Bump JamesIves/github-pages-deploy-action from 4.6.3 to 4.6.8

Bumps [JamesIves/github-pages-deploy-action](https://github.com/jamesives/github-pages-deploy-action) from 4.6.3 to 4.6.8.
- [Release notes](https://github.com/jamesives/github-pages-deploy-action/releases)
- [Commits](JamesIves/github-pages-deploy-action@v4.6.3...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] <support@github.com>

.github/workflows/pkgdown.yaml

@@ -78,7 +78,7 @@ jobs:
 
       - name: Deploy to GitHub pages 🚀
         if: github.event_name != 'merge_group' && github.event_name != 'pull_request'
-        uses: JamesIves/github-pages-deploy-action@v4.6.3
+        uses: JamesIves/github-pages-deploy-action@v4.6.8
         with:
           # We clean on releases because we want to remove old vignettes,
           # figures, etc. that have been deleted from the `main` branch.