gh-137400: Fix a crash when disabling profiling across all threads (gh-137471)

gh-137400: Fix a crash when disabling profiling across all threads (gh-137471)

The `PyEval_SetProfileAllThreads` function and other related functions
had a race condition on `tstate->c_profilefunc` that could lead to a
crash when disable profiling or tracing on all threads while another
thread is starting to profile or trace a a call.

There are still potential crashes when threads exit concurrently with
profiling or tracing be enabled/disabled across all threads.