Script to execute all notebooks inside the func-mooc.fr docker container

It would be nice to have a script part of the jupyterhub user docker image to be able to check that it's possible to execute all the cells of all the notebooks of the MOOC without raising exceptions and to log such exceptions otherwise.

We already do this check when we run the jupyter book command as part of the this github actions CI but this does not check that all the dependencies with the same versions are installed in the docker image used on the fun-mooc platform.

Start by inspecting the JupyterHub user Docker image and the existing GitHub Actions check that runs the jupyter book command. Determine how the MOOC notebooks are discovered and executed in the image; done means every notebook runs without unhandled exceptions, with failures logged.

Written by the indexing model from the issue text.