gh-116742: Fix subprocess test_check_output_timeout() (#130836)

gh-116742: Fix subprocess test_check_output_timeout() (#130836)

Fix a race condition in test_check_output_timeout() of
test_subprocess. Don't write into stdout anymore, since there is no
reliable way to synchronize the parent and the child processes.

Change the timeout from 3 seconds to 0.1 seconds, and remove
@requires_resource('walltime') decorator.