chore(gha): bump actions/deploy-pages from 3 to 4 (#266)

Also required to bump actions/upload-pages-artifact from 2 to 3.

Author: dependabot[bot]

.github/workflows/publish-documentation.yml

@@ -34,7 +34,7 @@ jobs:
         uses: ./.github/actions/build-documentation-site
 
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v3
         with:
           # Path of the directory containing the static assets.
           path: ./docs
@@ -54,4 +54,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v3
+        uses: actions/deploy-pages@v4