gh-85984: Document change in return type of tty functions (#110028)

Author: JelleZijlstra

Doc/library/tty.rst

@@ -43,6 +43,9 @@ The :mod:`tty` module defines the following functions:
    :func:`termios.tcsetattr`. The return value of :func:`termios.tcgetattr`
    is saved before setting *fd* to raw mode; this value is returned.
 
+   .. versionchanged:: 3.12
+      The return value is now the original tty attributes, instead of None.
+
 
 .. function:: setcbreak(fd, when=termios.TCSAFLUSH)
 
@@ -51,6 +54,9 @@ The :mod:`tty` module defines the following functions:
    :func:`termios.tcsetattr`. The return value of :func:`termios.tcgetattr`
    is saved before setting *fd* to cbreak mode; this value is returned.
 
+   .. versionchanged:: 3.12
+      The return value is now the original tty attributes, instead of None.
+
 
 .. seealso::