Subshell test flakiness

[davidbrochart]

See:

• https://github.com/ipython/ipykernel/actions/runs/13527491742/job/37801623045
• https://github.com/ipython/ipykernel/actions/runs/13527491742/job/37801624573
• https://github.com/ipython/ipykernel/actions/runs/13527491742/job/37801624996

[davidbrochart]

@ianthomas23 would you mind looking at this?

[ianthomas23]

@ianthomas23 would you mind looking at this?

Yes, I can do that.

[davidbrochart]

Since the release of v7.0.0a1, subshell tests timeout on Windows. It would be great if you could look at it too.