⬆️ Upgrade actions/upload-pages-artifact action to v4 (#25)

Author: Friedinger

.github/workflows/docs.yml

@@ -28,7 +28,7 @@ jobs:
 
       - name: Upload pages artifacts
         id: deployment
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         with:
           path: ./doc/api