Bump jupyterlab from 3.6.7 to 3.6.8

Bumps [jupyterlab](https://github.com/jupyterlab/jupyterlab) from 3.6.7 to 3.6.8.
- [Release notes](https://github.com/jupyterlab/jupyterlab/releases)
- [Changelog](https://github.com/jupyterlab/jupyterlab/blob/main/CHANGELOG.md)
- [Commits](https://github.com/jupyterlab/jupyterlab/compare/@jupyterlab/[email protected]...@jupyterlab/[email protected])

---
updated-dependencies:
- dependency-name: jupyterlab
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>