Using latest cothread on python3.11 with pyqt results in segfault

Calling this: cothread.iqt(run_exec=True)

Results in a segfault.

UPDATE 2

> Im seeing some issues with following the advice in update 1, things not working the way they used too.

UPDATE 1

> For the first fix below, QApplication.exec() should be spawned as a cothread, not called directly. Such as:
> cothread.Spawn(_qapp.exec)
>
> This works fine, but if you do any future yields or call any cothread functions which yield from the main thread it will segfault.
>
> So this works:
>
> ```
> def ticker():
> while True:
> cothread.Sleep(1)
> print("*** --------------------------------------------- tick")
>
> cothread.Spawn(_qapp.exec)
> cothread.Spawn(ticker)
> cothread.WaitForQuit()
> ```
> But this segfaults:
> ```
> cothread.Spawn(_qapp.exec)
> cothread.Yield()
> cothread.WaitForQuit()
> ```
> This is okayish as you typically spawning the exec thread is the last thing you do before running cothread.WaitForQuit().
> But obviously the root issue needs to be fixed.
>
> The second fix below suffers from the same issue.

Quick fixes:

- A quick fix can be made by either setting run_exec=False and calling QApplication.exec() manually.

- Or by removing the `cothread.Yield()` called immediately after` cothread.Spawn(getattr(_qapp, exec_name), stack_size = QT_STACK_SIZE)` in the iqt() function in input_hook.py

I don't yet understand the root cause of this issue, but will continue investigating.