Loaded replies before marshalling dump

[aidanharan]

Fixed the association dumps so that the replies were loaded before marshaling. Used following code to create the dumps:

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))

Fixes tests:

• MarshalSerializationTest#test_deserializing_rails_7_1_marshal_with_loaded_association_cache
• MarshalSerializationTest#test_deserializing_rails_6_1_marshal_with_loaded_association_cache