Coordinator ZkStateReader's watch is not removed upon collection deletion

Core registration in CoordinatorHttpCall correctly registers watch in ZkStateReader as in https://github.com/apache/solr/blob/f774922ecf44b18b78435cef8735618bb793ac30/solr/core/src/java/org/apache/solr/servlet/CoordinatorHttpSolrCall.java#L99, however there’s no code to remove such watch on collection deletion (state update).

For non coordinator node, it’s done at UnloadCoreOnDeleteWatcher at https://github.com/apache/solr/blob/main/solr/core/src/java/org/apache/solr/cloud/ZkController.java#L2869