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:production
...

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

Author: dependabot[bot]

requirements-notebook.txt

@@ -29,7 +29,7 @@ jsonschema==4.4.0
 jupyter-client==7.1.2
 jupyter-core==4.11.2
 jupyter-server==2.11.2
-jupyterlab==3.6.7
+jupyterlab==3.6.8
 jupyterlab-pygments==0.1.2
 jupyterlab-server==2.11.2
 kiwisolver==1.4.0