Fix url to core-mentorship mailing list (GH-11775)

Author: Mariatta

Doc/bugs.rst

@@ -89,4 +89,4 @@ any and all questions pertaining to the process of fixing issues in Python.
 
 .. _Documentation bugs: https://bugs.python.org/issue?@filter=status&@filter=components&components=4&status=1&@columns=id,activity,title,status&@sort=-activity
 .. _Python Developer's Guide: https://devguide.python.org/
-.. _core-mentorship mailing list: https://mail.python.org/mailman/listinfo/core-mentorship/
+.. _core-mentorship mailing list: https://mail.python.org/mailman3/lists/core-mentorship.python.org/