Flaky-test: BrokerRegistryIntegrationTest.cleanup

### Search before reporting

- [x] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar.

### Example failure

https://github.com/apache/pulsar/actions/runs/18344244449/job/52247551165#step:11:1206

### Exception stacktrace

```text
java.lang.RuntimeException: Broker took 10197ms to close
at org.apache.pulsar.broker.loadbalance.extensions.BrokerRegistryIntegrationTest.cleanup(BrokerRegistryIntegrationTest.java:73)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.testng.internal.invokers.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:139)
at org.testng.internal.invokers.MethodInvocationHelper.invokeMethodConsideringTimeout(MethodInvocationHelper.java:69)
at org.testng.internal.invokers.ConfigInvoker.invokeConfigurationMethod(ConfigInvoker.java:361)
at org.testng.internal.invokers.ConfigInvoker.invokeConfigurations(ConfigInvoker.java:296)
at org.testng.internal.invokers.TestMethodWorker.invokeAfterClassMethods(TestMethodWorker.java:222)
at org.testng.internal.invokers.TestMethodWorker.run(TestMethodWorker.java:131)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
at org.testng.TestRunner.privateRun(TestRunner.java:829)
at org.testng.TestRunner.run(TestRunner.java:602)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:437)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:431)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:391)
at org.testng.SuiteRunner.run(SuiteRunner.java:330)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:95)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1256)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1176)
at org.testng.TestNG.runSuites(TestNG.java:1099)
at org.testng.TestNG.run(TestNG.java:1067)
at org.apache.maven.surefire.testng.TestNGExecutor.run(TestNGExecutor.java:155)
at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.executeSingleClass(TestNGDirectoryTestSuite.java:102)
at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.executeLazy(TestNGDirectoryTestSuite.java:117)
at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.execute(TestNGDirectoryTestSuite.java:86)
at org.apache.maven.surefire.testng.TestNGProvider.invoke(TestNGProvider.java:137)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:385)
at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:162)
```

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Start with BrokerRegistryIntegrationTest.cleanup at line 73 and review the linked GitHub Actions failure showing the broker close timeout. Reproduce the flaky test and investigate the cleanup behavior; done means the integration test closes the broker within its expected time without the reported exception.

Written by the indexing model from the issue text.