docs: Add a link to future cleanup ticket.

Co-authored-by: Kyle McCormick <kyle@axim.org>

cms/djangoapps/contentstore/rest_api/v1/serializers/course_waffle_flags.py

@@ -45,6 +45,8 @@ class CourseWaffleFlagsSerializer(serializers.Serializer):
         This used to be based on a waffle flag but the flag is being removed so we
         default it to true for now until we can remove the need for it from the consumers
         of this serializer and the related APIs.
+
+        See https://github.com/openedx/edx-platform/issues/37497
         """
         return True