Update actions/upload-pages-artifact action to v4

Author: renovate[bot]

.github/workflows/pages.yml

@@ -40,7 +40,7 @@ jobs:
           source: ./docs
           destination: ./_site
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3
+        uses: actions/upload-pages-artifact@7b1f4a764d45c48632c6b24a0339c27f5614fb0b # v4
 
   # Deployment job
   deploy: