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

(cherry picked from commit e01e442125bbc98e6dab66f38ecc6c45f69e6587)

Co-authored-by: Andre Delfino <adelfino@gmail.com>
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index 189d49e..778fd40 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -1025,7 +1025,7 @@
       :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