Bump @jupyterlab/builder from 4.4.5 to 4.4.9 in /js

Bumps [@jupyterlab/builder](https://github.com/jupyterlab/jupyterlab) from 4.4.5 to 4.4.9.
- [Release notes](https://github.com/jupyterlab/jupyterlab/releases)
- [Changelog](https://github.com/jupyterlab/jupyterlab/blob/main/RELEASE.md)
- [Commits](https://github.com/jupyterlab/jupyterlab/compare/@jupyterlab/builder@4.4.5...@jupyterlab/builder@4.4.9)

---
updated-dependencies:
- dependency-name: "@jupyterlab/builder"
  dependency-version: 4.4.9
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

js/package.json

@@ -53,7 +53,7 @@
     "@babel/core": "^7.28.4",
     "@babel/eslint-parser": "^7.28.0",
     "@babel/preset-env": "^7.28.3",
-    "@jupyterlab/builder": "^4.4.5",
+    "@jupyterlab/builder": "^4.4.9",
     "babel-jest": "^30.1.2",
     "cpy-cli": "^6.0.0",
     "eslint": "^8.57.1",