Bump JamesIves/github-pages-deploy-action from 4.6.8 to 4.6.9

Bumps [JamesIves/github-pages-deploy-action](https://github.com/jamesives/github-pages-deploy-action) from 4.6.8 to 4.6.9.
- [Release notes](https://github.com/jamesives/github-pages-deploy-action/releases)
- [Commits](JamesIves/github-pages-deploy-action@v4.6.8...v4.6.9)

---
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]>

Author: dependabot[bot]

.github/workflows/ci-ubuntu.yml

@@ -186,7 +186,7 @@ jobs:
 ########################################################################
 
       - name: Deploy HTML
-        uses: JamesIves/[email protected].8
+        uses: JamesIves/[email protected].9
         if: ${{ success() && env.AGDA_DEPLOY }}
         with:
           branch: gh-pages