Certain windows tests are timing out since 1.31.0 #2688

In the dart-lang/ai repo, the package at pkgs/dart_mcp has been timing out ever since the 1.31.0 release on windows.

It appears that the test runner is just never exiting, and all the tests are running, although we never see the summary message either.

Example failure https://github.com/dart-lang/ai/actions/runs/28306293107

Reverting to test 1.30.0 fixes things dart-lang/ai#509