Bump kafkaVersion from 3.8.1 to 3.9.0

Bumps `kafkaVersion` from 3.8.1 to 3.9.0.

Updates `org.apache.kafka:kafka-clients` from 3.8.1 to 3.9.0

Updates `org.apache.kafka:kafka-streams` from 3.8.1 to 3.9.0

Updates `org.apache.kafka:kafka-streams-test-utils` from 3.8.1 to 3.9.0

---
updated-dependencies:
- dependency-name: org.apache.kafka:kafka-clients
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.apache.kafka:kafka-streams
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.apache.kafka:kafka-streams-test-utils
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle.kts

@@ -76,7 +76,7 @@ subprojects {
         set("junitPioneerVersion", "2.2.0")     // https://mvnrepository.com/artifact/org.junit-pioneer/junit-pioneer
         set("mockitoVersion", "5.14.2")          // https://mvnrepository.com/artifact/org.mockito/mockito-junit-jupiter
         // Update kafka_version in `.github/workflows/build.yml` when updating this version
-        set("kafkaVersion", "3.8.1")            // https://mvnrepository.com/artifact/org.apache.kafka
+        set("kafkaVersion", "3.9.0")            // https://mvnrepository.com/artifact/org.apache.kafka
         set("confluentVersion", "7.7.2")        // https://packages.confluent.io/maven/io/confluent/kafka-schema-registry-client
         set("testContainersVersion", "1.19.8")  // https://mvnrepository.com/artifact/org.testcontainers/testcontainers
     }