KIP-1125 — Remove Invalid 'numberOfOpenFiles' Metric from RocksDB State Store

Discussion Kafka 5.0 StreamsMetrics

Removes the `opennumberfiles` metric from the RocksDB state store in Kafka Streams, which always returns -1 since RocksDB 8.7.3 removed the underlying `NO_FILE_CLOSES` internal counter. The stale metric misleads operators and can trigger false alarms in monitoring systems.

Details