Mark unbound method removal as done.

pep-3100.txt

@@ -121,7 +121,7 @@ To be removed:
 * ```x```: use ``repr(x)`` [2]_ [done]
 * The ``<>`` operator: use ``!=`` instead [3]_ [done]
 * The __mod__ and __divmod__ special methods on float. [they should stay] [21]_
-* Drop unbound methods [7]_ [25]_
+* Drop unbound methods [7]_ [25]_ [done]
 * METH_OLDARGS
 * WITH_CYCLE_GC [done]
 * __getslice__, __setslice__, __delslice__ [#sequence-types]_;