Bug report

Bug description:

In #104826 (backported to 3.12 in #105277) to fix #104690 disallowed creating new threads during interpreter finalization. This poses a problem on windows because the Popen._communicate uses a thread (see matplotlib/matplotlib#27437 (comment) for discussion).

In Matplotlib we are holding onto a latex process and triggering this via a weakref finalize, but a minimal reproducer is:

from subprocess import Popen, PIPE
import atexit

# anything that holds stdin and stdout should work
proc = Popen(['powershell'], stdin=PIPE, stdout=PIPE)

def cleanup():
    print('hi bob')
    proc.kill()
    proc.communicate()

atexit.register(cleanup)

xref matplotlib/matplotlib#27437

CPython versions tested on:

3.12

Operating systems tested on:

Windows