Bump jupyterlab from 4.5.7 to 4.5.9 in /site

Bumps [jupyterlab](https://github.com/jupyterlab/jupyterlab) from 4.5.7 to 4.5.9.
- [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/lsp@4.5.7...@jupyterlab/lsp@4.5.9)

---
updated-dependencies:
- dependency-name: jupyterlab
  dependency-version: 4.5.9
  dependency-type: direct:production
...

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

Author: dependabot[bot]

site/requirements.txt

@@ -1,4 +1,4 @@
 jupyterlite-core==0.6.4
-jupyterlab==4.5.7
+jupyterlab==4.5.9
 notebook==7.5.6
 jupyterlite-pyodide-kernel==0.6.1