refer to webpack config in package.json under jupyter

Author: emilykl

.github/workflows/check-js-build.yml

@@ -71,7 +71,6 @@ jobs:
         else
         echo "✅ Build artifacts match expected output (ignoring known 'load' hash in package.json)."
         fi
-
     - name: Store the build artifacts from plotly/labextension
       uses: actions/upload-artifact@v4
       if: failure()

js/package.json

@@ -30,6 +30,7 @@
   },
   "jupyterlab": {
     "mimeExtension": true,
-    "outputDir": "../plotly/labextension"
+    "outputDir": "../plotly/labextension",
+    "webpackConfig": "./webpack.config.js"
   }
 }