deps: update dependency org.apache.kafka:kafka-clients to v2.6.0 (#279)

Author: renovate-bot

pubsublite-kafka-shim/pom.xml

@@ -28,7 +28,7 @@
  <dependency>
  <groupId>org.apache.kafka</groupId>
  <artifactId>kafka-clients</artifactId>
- <version>2.5.0</version>
+ <version>2.6.0</version>
  </dependency>
  <dependency>
  <groupId>io.grpc</groupId>