build(deps): bump notebook from 5.6.0 to 5.7.8 in /lib/bazel

Bumps [notebook](https://github.com/jupyter/jupyterhub) from 5.6.0 to 5.7.8.
- [Release notes](https://github.com/jupyter/jupyterhub/releases)
- [Changelog](https://github.com/jupyterhub/jupyterhub/blob/master/CHECKLIST-Release.md)
- [Commits](https://github.com/jupyter/jupyterhub/commits)

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

Author: dependabot[bot]

lib/bazel/requirements.txt

@@ -44,7 +44,7 @@ pyserial==3.2.1
 
 # Install Jupyter notebook (no direct import).
 jupyter==1.0.0
-notebook==5.6.0
+notebook==5.7.8
 backports.shutil_get_terminal_size==1.0.0
 
 # Install Google Cloud APIs.