Dependency cleanup - Kafka binder

Revmoe unnecessary explicit depdency of kafka-clients in the binder

binders/kafka-binder/spring-cloud-stream-binder-kafka/pom.xml

@@ -37,10 +37,6 @@
 			<artifactId>spring-boot-autoconfigure</artifactId>
 			<optional>true</optional>
 		</dependency>
-		<dependency>
-			<groupId>org.apache.kafka</groupId>
-			<artifactId>kafka-clients</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>org.springframework.kafka</groupId>
 			<artifactId>spring-kafka</artifactId>