Flaky-test: BrokerRegistryMetadataStoreIntegrationTest.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/18802878674/job/53653078467#step:11:676

### Exception stacktrace

```text
[ERROR] org.apache.pulsar.broker.loadbalance.extensions.BrokerRegistryMetadataStoreIntegrationTest.cleanup -- Time elapsed: 11.19 s <<< FAILURE!
java.lang.RuntimeException: Broker took 10272ms 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)
```

### Are you willing to submit a PR?

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

Start with the linked GitHub Actions failure and inspect cleanup in BrokerRegistryIntegrationTest.java at line 73, where the broker close timeout is reported. Reproduce the failure in BrokerRegistryMetadataStoreIntegrationTest.cleanup and trace why shutdown exceeds the limit. Done means the test completes reliably without the broker-close timeout.

Written by the indexing model from the issue text.