Multiprocessing: facilitate worker processes printing to GUI shell

Feature or enhancement

Currently, multiprocessing functions can be run in IDLE. However, the output of these functions is not displayed in the IDLE shell. This is because the fork done by multiprocessing does not duplicate or inherit the socket connection (https://stackoverflow.com/a/35297841/14432236).

Pitch

The output of multiprocessing functions should be displayed in the IDLE shell if the shell is run. For instance, this example code will be able to run without displaying a termination message if multiprocessing is enabled: https://github.com/python/cpython/issues/92571

Previous discussion

I believe that the last couple bugs that I filed are because of this issue: https://github.com/python/cpython/issues/92622 and https://github.com/python/cpython/issues/92571

この issue にはファイルもテストも記載されていません。まず関連する issue 92571 と 92622 を確認し、multiprocessing の fork が IDLE shell で使用される socket 接続にどのような影響を与えるかを調査してください。worker プロセスの出力が終了メッセージなしで IDLE shell に表示されれば完了です。