Test with JupyterLab 4.1 and Notebook 4.1 prereleases

[bollwyvl]

Elevator Pitch

Add a matrix factor for jupyterlab 4.1.x, and gather findings here.

Motivation

In some demos, it was noted that new keyboard shortcut scopes for ArrowLeft and ArrowRight are no longer overloaded, and trigger awkward cell collapsing behavior.

Design Ideas

• add conda-forge/label/jupyterlab_beta
• add jupyterlab
• fix selector scopes
• update tests
• update docs
  • watch lite, maybe pull RTD builds
• ???

[nthiery]

Hello,
I confirm the "awkward cell collapsing behavior" of left/right arrow and thereby space/shift-space with jupyterlab=4.1. So I rolled back JupyterLab to 4.0.12.

[nthiery]

As a data point: also space / shift space tend to scroll down and up instead of switching to the next/prev fragment like up-down arrows.