Update actions/upload-pages-artifact action to v4

Author: renovate[bot]

.github/workflows/jekyll-gh-pages.yml

@@ -44,7 +44,7 @@ jobs:
           source: ./
           destination: ./_site
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3.0.1
+        uses: actions/upload-pages-artifact@7b1f4a764d45c48632c6b24a0339c27f5614fb0b # v4.0.0
 
   # Deployment job
   deploy: