Loaded replies before marshalling dump (#1116)

To create the dumps with associates use:

ActiveRecord::Marshalling.format_version = 6.1
topic = Topic.find(1)
topic.replies.load
File.binwrite(marshal_fixture_path("rails_6_1_topic_associations"), Marshal.dump(topic))

ActiveRecord::Marshalling.format_version = 7.1
topic = Topic.find(1)
topic.replies.load
File.binwrite(marshal_fixture_path("rails_7_1_topic_associations"), Marshal.dump(topic))

Author: aidanharan