Simplify Windows write I/O around consoles on Windows 8+

Feature or enhancement

Proposal:

In bpo-11395 from 2011, Windows Python needed to check on every write if a write was to a tty / console object and limit the size of the write to avoid an OS error on write. With Windows 8 and above, the Windows subsystem has been updated and this check is no longer necessary. It is also not necessary to split the write into smaller pieces (which resulted in gh-110913 and gh-82052).

Based on PEP 11, the last Windows 8 support ended in 2023, so the isatty + limited write size is no longer needed on any currently supported Windows platform (Pipes are still limited write size).

That large writes work is tested in test_os, test_write_windows_console

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

https://github.com/python/cpython/issues/55604#issuecomment-1093537612

Linked PRs

• gh-121941

Start with the Windows console write coverage in test_os and test_write_windows_console, then trace the related Windows write path. The change is complete when console writes no longer require the obsolete checks or splitting on supported Windows versions, pipe write limits remain, and the existing large-write tests pass.