gh-110904: Recommend windows-curses in the curses HOWTO

The HOWTO pointed at UniCurses, which is unmaintained and exposes its own
API.  windows-curses provides the standard curses interface on Windows, so
existing code runs unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: serhiy-storchaka

Doc/howto/curses.rst

@@ -52,8 +52,8 @@ code, all the functions described here will probably be available.  The older
 versions of curses carried by some proprietary Unixes may not support
 everything, though.
 
-The Windows version of Python doesn't include the :mod:`curses`
-module.  A ported version called :pypi:`UniCurses` is available.
+The Windows version of Python doesn't include the :mod:`curses` module.
+The third-party :pypi:`windows-curses` package provides the same interface on Windows.
 
 
 The Python curses module