We need to close all resources created so far, and currently we don't.
See in particular:

• org.hibernate.search.v6poc.engine.impl.SearchMappingRepositoryBuilderImpl#build
• org.hibernate.search.v6poc.engine.impl.IndexManagerBuildingStateHolder
• The various indexing processor builders in the POJO mapper
• org.hibernate.search.v6poc.backend.lucene.index.impl.LuceneLocalDirectoryIndexManagerBuilder#createIndexWriter