[issue43016] Improve tests for curses

[Serhiy Storchaka]

Change by Serhiy Storchaka <storchaka+cpython at gmail.com>:


----------
pull_requests: +23215
pull_request: https://github.com/python/cpython/pull/24401

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue43016>
_______________________________________