In total, test_posix.py and test_os.py are the second largest test in the Python test suite: 8,193 lines.

I propose to:

• (1) merge these two files into a new single test_os package
• and (2) split these files into smaller files to ease their maintenance.

Linked PRs

• gh-139322: Create test_os package #139323
• gh-139322: Create test_os package #139453
• gh-139322: Remove redundant test_os.Win32ErrorTests #139477
• gh-139322: Create test_os.test_process #139480
• gh-139322: Reenable test_os.test_getlogin() #139498