Use the `comm` package

[jtpio]

Problem

It should now be possible to use the new comm package: https://pypi.org/project/comm/

Currently there is a mock for ipykernel here: https://github.com/jupyterlite/pyodide-kernel/tree/main/packages/pyodide-kernel/py/ipykernel

Which hopefully could be removed.

Proposed Solution

Use the comm package so can get rid of one of the mocks.

Additional context

jupyterlite/jupyterlite#18

[jtpio]

Actually not sure since ipywidgets initially dropped ipykernel, but then added it back in jupyter-widgets/ipywidgets#3749.

[jtpio]

Hmm looks like the latest ipywidgets releases break widgets in the Pyodide kernel:

The latest that seems to work is 8.0.4:

[jtpio]

The latest that seems to work is 8.0.4:

cc @martinRenou who might know if this is related to a change in ipywidgets in 8.0.5 or 8.0.6.

[bollwyvl]

Yep bottom pins are tighter now, basically to get around the structuredClone SNAFU. Need to bump the mock packages... Older 8.x and 7.x ones will be compatible. But also should be pinning for reproducible builds with front and backend. As for comm.... Well that's not been very smooth either, and the ipykernel dep is still carried by ipywidgets.

[jtpio]

@martinRenou looks like the 8.1.0 release of package of widgets means we could start using the comm package here? https://github.com/jupyter-widgets/ipywidgets/releases/tag/8.1.0

Which would help fix jupyter-widgets/ipywidgets#3819

[martinRenou]

Yes!

[bollwyvl]

Better do something, because jupyter-widgets/ipywidgets#3811 (comment)