Remove unused import (#5843)

Signed-off-by: Hai Yan <oeyh@amazon.com>

Author: oeyh

data-prepper-plugins/kafka-plugins/src/test/java/org/opensearch/dataprepper/plugins/kafka/buffer/KafkaBufferTest.java

@@ -41,7 +41,6 @@
 import org.opensearch.dataprepper.plugins.kafka.producer.KafkaCustomProducerFactory;
 import org.opensearch.dataprepper.plugins.kafka.producer.ProducerWorker;
 import org.opensearch.dataprepper.plugins.kafka.util.MessageFormat;
-import org.opensearch.dataprepper.plugins.codec.CompressionOption;
 import org.slf4j.MDC;
 
 import java.time.Duration;