gh-70474: [doc] fix wording of GET_ANEXT doc (GH-94048)

(cherry picked from commit 9af6b75)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>

Author: miss-islington

Doc/library/dis.rst

@@ -591,8 +591,8 @@ the original TOS1.
 
 .. opcode:: GET_ANEXT
 
-   Implements ``PUSH(get_awaitable(TOS.__anext__()))``.  See ``GET_AWAITABLE``
-   for details about ``get_awaitable``
+   Pushes ``get_awaitable(TOS.__anext__())`` to the stack.  See
+   ``GET_AWAITABLE`` for details about ``get_awaitable``.
 
    .. versionadded:: 3.5