Support derived deleteBy methods.

In Spring Data Neo4j 6.1.1 (and probably earlier), I noticed that the derived "deleteByX" queries actually don't delete; they do a find instead. 
While it's easy enough to just write a custom delete query, I point this out because it's explicitly a feature in the documentation:
https://docs.spring.io/spring-data/neo4j/docs/current/reference/html/#repositories.core-concepts

Thanks!