Remove logic to auto-detect Unconverted pets (fixes Baby Pteri bug)

Two motivations here:

1. Unconverted pets should no longer exist on Neopets.com (and we
   especially don't expect new ones), so this logic helps no one.
2. The Baby Pteri keeps getting overridden to be marked as Unconverted
   because it has only one asset, which is incorrect.

A decent heuristic for a bygone era, goodbye!

app/models/pet_state.rb

@@ -169,7 +169,6 @@ class PetState < ApplicationRecord
       end
     end
     pet_state.parent_swf_asset_relationships_to_update = relationships
-    pet_state.unconverted = (relationships.size == 1)
     pet_state
   end
 end