runtime: TestCgoLockOSThreadExit failures

[gopherbot]

#!watchflakes
default <- pkg == "runtime" && test == "TestCgoLockOSThreadExit"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestCgoLockOSThreadExit
=== PAUSE TestCgoLockOSThreadExit
=== CONT  TestCgoLockOSThreadExit
    proc_test.go:987: /home/swarming/.swarming/w/ir/x/t/go-build473597380/testprogcgo.exe LockOSThreadMain (3.178162777s): ok
    proc_test.go:993: /home/swarming/.swarming/w/ir/x/t/go-build473597380/testprogcgo.exe LockOSThreadAlt: exec: WaitDelay expired before I/O complete
--- FAIL: TestCgoLockOSThreadExit (8.40s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime" && test == "TestCgoLockOSThreadExit"

2025-12-05 18:38 gotip-linux-amd64-race go@54e55400 runtime.TestCgoLockOSThreadExit (log)

=== RUN   TestCgoLockOSThreadExit
=== PAUSE TestCgoLockOSThreadExit
=== CONT  TestCgoLockOSThreadExit
    proc_test.go:987: /home/swarming/.swarming/w/ir/x/t/go-build473597380/testprogcgo.exe LockOSThreadMain (3.178162777s): ok
    proc_test.go:993: /home/swarming/.swarming/w/ir/x/t/go-build473597380/testprogcgo.exe LockOSThreadAlt: exec: WaitDelay expired before I/O complete
--- FAIL: TestCgoLockOSThreadExit (8.40s)

— watchflakes