Update actions/deploy-pages action to v4 (#20)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/deploy.yml

@@ -35,4 +35,4 @@ jobs:
       - name: Deploy to GitHub Pages
         id: deployment
         # https://github.com/actions/deploy-pages
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v4