std.Io.Threaded: work around parking futex bug

This commit should be reverted - it's testing a hypothesis that Windows
is deadlocking due to bug in the implementation of
std.Io.Threaded.parking_futex
5312063138Andrew Kelley committed on 2/2/2026, 10:25:27 PMparenteb74e23
1 file changedLine totals unavailable