subclass of undefined DUL class

https://databus.dbpedia.org/ontologies/dbpedia.org/ontology--DEV/2024.07.29-001000/ontology--DEV_type=parsed.ttl

This subclass link is defective (empty local name)
```ttl
dbo:PenaltyShootOut a owl:Class ;
  rdfs:subClassOf dul: .
```