flakey test: brave.kafka1.clients.ITKafkaTracing.poll_creates_one_consumer_span_per_topic

[codefromthecrypt]

This only fails in invoker tests that use an old version of kafka, and currently only in JDK 21...

https://github.com/openzipkin/brave/actions/runs/7441570423/job/20243845744?pr=1395

 Error: [ERROR] Tests run: 7, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 11.10 s <<< FAILURE! -- in brave.kafka1.clients.ITKafkaTracing
Error: [ERROR] brave.kafka1.clients.ITKafkaTracing.poll_creates_one_consumer_span_per_topic -- Time elapsed: 0.260 s <<< FAILURE!
[INFO] org.opentest4j.AssertionFailedError: 
[INFO] Orphaned span found: {"traceId":"dd8fab380d3ed556","id":"5a918d7255a7de40","localEndpoint":{"serviceName":"ITKafkaTracing","ipv4":"127.0.0.1"},"annotations":[{"timestamp":1704673318869812,"value":"brave.flush"}],"tags":{"kafka.key":"foo","kafka.topic":"continues_a_trace_when_only_trace_id_propagated"}}
[INFO] Look for code missing span.flush() or span.finish().
[INFO] 	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502)
[INFO] 	at brave.test.IntegrationTestSpanHandler.doTakeSpan(IntegrationTestSpanHandler.java:210)
[INFO] 	at brave.test.IntegrationTestSpanHandler.doTakeSpan(IntegrationTestSpanHandler.java:320)
[INFO] 	at brave.test.IntegrationTestSpanHandler.takeRemoteSpan(IntegrationTestSpanHandler.java:238)
[INFO] 	at brave.kafka.clients.ITKafkaTracing.takeConsumerSpan(ITKafkaTracing.java:121)
[INFO] 	at brave.kafka.clients.ITKafkaTracing.poll_creates_one_consumer_span_per_topic(ITKafkaTracing.java:140)
[INFO] 	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
[INFO] 	at brave.test.IntegrationTestSpanHandler.interceptTestMethod(IntegrationTestSpanHandler.java:397)
[INFO] 	at brave.test.IntegrationTestSpanHandler.interceptTestMethod(IntegrationTestSpanHandler.java:397)
[INFO] 	at brave.test.IntegrationTestSpanHandler.interceptTestMethod(IntegrationTestSpanHandler.java:397)
[INFO] 	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
[INFO] 	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)