[doc] Fix link to abc.ABCMeta.register in Glossary (GH-22932)

(cherry picked from commit e01e442)

Co-authored-by: Andre Delfino <[email protected]>

Author: miss-islington

Doc/glossary.rst

@@ -1025,7 +1025,7 @@ Glossary
       :meth:`index`, :meth:`__contains__`, and
       :meth:`__reversed__`. Types that implement this expanded
       interface can be registered explicitly using
-      :func:`~abc.register`.
+      :func:`~abc.ABCMeta.register`.
 
    single dispatch
       A form of :term:`generic function` dispatch where the implementation is