Remove deprecated `master_open` and `slave_open` from `pty`

# Feature or enhancement

They were deprecated in https://github.com/python/cpython/issues/85984 and https://github.com/python/cpython/commit/244d4cd9d22d73fb3c0938937c4f435bd68f32d4


### Linked PRs
* gh-118826