bpo-43774: Remove --without-cycle-gc doc (GH-25364)

The configure --without-cycle-gc option has been removed in Python
2.3 by the commit cccd1e72481106b0a373117f32fda6261f3141a7. It's now
time to remove the last reference to it in the documentation.

diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst
index bc85a05ff2f850345fdda1b6f3d3ae7cad8a49af..561d1c616cc10e1dfc511ff999ecbc9fd6f21fc9 100644 (file)
--- a/Doc/extending/extending.rst
+++ b/Doc/extending/extending.rst
@@ -911,12 +911,7 @@ the cycle itself.
 The cycle detector is able to detect garbage cycles and can reclaim them.
 The :mod:`gc` module exposes a way to run the detector (the
 :func:`~gc.collect` function), as well as configuration
-interfaces and the ability to disable the detector at runtime.  The cycle
-detector is considered an optional component; though it is included by default,
-it can be disabled at build time using the :option:`!--without-cycle-gc` option
-to the :program:`configure` script on Unix platforms (including Mac OS X).  If
-the cycle detector is disabled in this way, the :mod:`gc` module will not be
-available.
+interfaces and the ability to disable the detector at runtime.
 
 
 .. _refcountsinpython: