Update actions/upload-pages-artifact action to v4

Author: renovate[bot]

.github/workflows/docs.yml

@@ -43,7 +43,7 @@ jobs:
           npm run docs
           touch ./docs/build/site/.nojekyll
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         with:
           # Upload docs
           path: "./docs/build/site"