Update actions/upload-pages-artifact action to v4

Author: OpenStack K8s CI

.github/workflows/documentation.yaml

@@ -48,7 +48,7 @@ jobs:
           docs/build-docs.sh
       - name: Upload artifacts
         if: ${{ github.ref == 'refs/heads/main' }}
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         with:
           path: docs/build/html/
   deploy: