gh-144513: Skip critical section locking during stop-the-world (gh-144524)

gh-144513: Skip critical section locking during stop-the-world (gh-144524)

When the interpreter is in a stop-the-world pause, critical sections
don't need to acquire locks since no other threads can be running.
This avoids a potential deadlock where lock fairness hands off ownership
to a thread that has already suspended for stop-the-world.