Python 3.15.0 alpha 4

Edit: This 3.15.0a4 was accidentally built against `main` from 2025-12-23 instead of 2026-01-13, so 3.15.0a5 is an extra release correctly built against 2026-01-14. This is an early developer preview of Python 3.15 www.python.org/downloads/release/python-3150a4/ Major new features of the 3.15 series, compared to 3.14 Python 3.15 is still in development. This release, 3.15.0a4, is the fourth of seven planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments. Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far: PEP 799 :