test_ioctl is skipped because of setsid()

[vstinner]

Python test runner "regrtest" uses process groups to be able to kill child processes of worker processes. Tests are run in subprocesses to run them in parallel and to catch bugs.

Problem: if setsid() is called (after fork), test_ioctl fails to open /dev/tty.

I propose to not use setsid() when running tests using TTY, such as test_ioctl.

Linked PRs

• gh-119273: Don't run test_ioctl in a process group #119275