Bump org.apache.kafka:kafka-streams-test-utils in /aggregator

Bumps org.apache.kafka:kafka-streams-test-utils from 3.9.0 to 4.1.1.

---
updated-dependencies:
- dependency-name: org.apache.kafka:kafka-streams-test-utils
  dependency-version: 4.1.1
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

aggregator/pom.xml

@@ -25,7 +25,7 @@
         <maven.compiler.release>21</maven.compiler.release>
         <compiler-plugin.version>3.14.1</compiler-plugin.version>
         <surefire-plugin.version>3.5.4</surefire-plugin.version>
-        <kafka.version>3.9.0</kafka.version>
+        <kafka.version>4.1.1</kafka.version>
         <confluent.platform.version>8.1.1</confluent.platform.version>
     </properties>
     <dependencyManagement>