Fix stale example on tuple_fetch

Author: lukaszsamson

lib/elixir/lib/module/types/descr.ex

@@ -4946,12 +4946,12 @@ defmodule Module.Types.Descr do
       iex> tuple_fetch(tuple([integer(), atom()]), 0)
       {false, integer()}
 
-      iex> tuple_fetch(bare_union(tuple([integer()]), tuple([integer(), atom()])), 1)
-      {true, atom()}
-
       iex> tuple_fetch(dynamic(), 0)
       {true, dynamic()}
 
+      iex> tuple_fetch(bare_union(tuple([integer()]), tuple([integer(), atom()])), 1)
+      :badindex
+
       iex> tuple_fetch(integer(), 0)
       :badtuple