fix(deps): update dependency org.apache.kafka:kafka-clients to v4.2.0 (#431)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Sverre H. Huseby <shh@thathost.com>

Author: renovate[bot]

pom.xml

@@ -9,8 +9,8 @@
     <properties>
         <java.version>25</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <kafka.version>4.1.1</kafka.version>
-        <k3a.embedded.version>0.7.0+${kafka.version}</k3a.embedded.version>
+        <kafka.version>4.2.0</kafka.version>
+        <k3a.embedded.version>0.8.0+${kafka.version}</k3a.embedded.version>
         <maven-surefire.version>3.5.4</maven-surefire.version>
         <prometheus.version>1.5.0</prometheus.version>
     </properties>