Update dependency @jupyterlab/builder to v4

Author: renovate[bot]

finspector/labextension/package.json

@@ -31,7 +31,7 @@
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "devDependencies": {
-    "@jupyterlab/builder": "^3.6.3",
+    "@jupyterlab/builder": "^4.0.0",
     "rimraf": "^2.6.1",
     "webpack": "^5.83.1"
   },