Jupytext - latest nbclassic compatibility issue

[GeorgianaElena]

Context

Jupytext is not compatibile with latest nbclassic version. Context about this available at #2302

• PR to solve this on the nbclassic side at Remove redirect from /notebooks to /files jupyter/nbclassic#235
• Workarounds described in Clicking on .py file downloads it instead of opening it. mwouts/jupytext#1051 (comment) and Clicking on .py file downloads it instead of opening it. mwouts/jupytext#1051 (comment)

Proposal

I believe we currently have two options of fixing this on our side:

• install https://github.com/mwouts/nbclassic.git@do_not_redirect_notebook_to_files in this image (or the hub image, but installing it here is less intrusive) -> this has been confirmed to be working in the LIS hub
• go back to the working version in pin nbclassic < 5 and go back to using NotebookApp, as we did for utoronto in [utoronto] Undo Jupyter ServerApp usage to fix jupyter-nbcontrib-extensions #2411

Once a new nbclassic version with jupyter/nbclassic#235 is released, these workarounds won't be needed anymore.

Updates and actions

No response