Allow wakeup mutex to be used in trap context. (ruby#13684)

Author: ioquatix

thread.c

@@ -2847,6 +2847,7 @@ rb_thread_io_close_interrupt(struct rb_io *io)
 
     // This is used to ensure the correct execution context is woken up after the blocking operation is interrupted:
     io->wakeup_mutex = rb_mutex_new();
+    rb_mutex_allow_trap(io->wakeup_mutex, 1);
 
     // We need to use a mutex here as entering the fiber scheduler may cause a context switch:
     VALUE result = rb_mutex_synchronize(io->wakeup_mutex, thread_io_close_notify_all, (VALUE)io);