Flaky-test: MultiTopicsReaderTest.testMultiTopic

### Search before asking

- [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/4944000364/jobs/8839164318?pr=20297#step:10:732

### Exception stacktrace

```
Error: Tests run: 18, Failures: 1, Errors: 0, Skipped: 10, Time elapsed: 135.535 s <<< FAILURE! - in org.apache.pulsar.client.impl.MultiTopicsReaderTest
Error: org.apache.pulsar.client.impl.MultiTopicsReaderTest.stateCheck[public void org.apache.pulsar.client.impl.MultiTopicsReaderTest.testMultiTopic() throws java.lang.Exception](0) Time elapsed: 81.829 s <<< FAILURE!
org.apache.pulsar.client.admin.PulsarAdminException$ConflictException: Cluster already exists
at org.apache.pulsar.client.admin.PulsarAdminException.wrap(PulsarAdminException.java:252)
at org.apache.pulsar.client.admin.internal.BaseResource.sync(BaseResource.java:352)
at org.apache.pulsar.client.admin.internal.ClustersImpl.createCluster(ClustersImpl.java:78)
at org.apache.pulsar.client.impl.MultiTopicsReaderTest.setup(MultiTopicsReaderTest.java:79)
at org.apache.pulsar.tests.TestRetrySupport.stateCheck(TestRetrySupport.java:60)
at jdk.internal.reflect.GeneratedMethodAccessor113.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.testng.internal.invokers.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:139)
at org.testng.internal.invokers.MethodInvocationHelper.invokeMethodConsideringTimeout(MethodInvocationHelper.java:69)
at org.testng.internal.invokers.ConfigInvoker.invokeConfigurationMethod(ConfigInvoker.java:361)
at org.testng.internal.invokers.ConfigInvoker.invokeConfigurations(ConfigInvoker.java:296)
at org.testng.internal.invokers.TestInvoker.runConfigMethods(TestInvoker.java:823)
at org.testng.internal.invokers.TestInvoker.invokeMethod(TestInvoker.java:590)
at org.testng.internal.invokers.TestInvoker.retryFailed(TestInvoker.java:263)
at org.testng.internal.invokers.MethodRunner.runInSequence(MethodRunner.java:62)
at org.testng.internal.invokers.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:969)
at org.testng.internal.invokers.TestInvoker.invokeTestMethods(TestInvoker.java:194)
at org.testng.internal.invokers.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:148)
at org.testng.internal.invokers.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
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)
at org.apache.maven.surefire.booter.ForkedBooter.run(ForkedBooter.java:507)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:495)
Suppressed: org.apache.pulsar.client.admin.PulsarAdminException$ConflictException: Cluster already exists
at org.apache.pulsar.client.admin.internal.BaseResource.getApiException(BaseResource.java:287)
at org.apache.pulsar.client.admin.internal.BaseResource$1.failed(BaseResource.java:136)
at org.glassfish.jersey.client.JerseyInvocation$1.failed(JerseyInvocation.java:882)
at org.glassfish.jersey.client.JerseyInvocation$1.completed(JerseyInvocation.java:863)
at org.glassfish.jersey.client.ClientRuntime.processResponse(ClientRuntime.java:229)
at org.glassfish.jersey.client.ClientRuntime.access$200(ClientRuntime.java:62)
at org.glassfish.jersey.client.ClientRuntime$2.lambda$response$0(ClientRuntime.java:173)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:288)
at org.glassfish.jersey.client.ClientRuntime$2.response(ClientRuntime.java:173)
at org.apache.pulsar.client.admin.internal.http.AsyncHttpConnector.lambda$apply$1(AsyncHttpConnector.java:254)
at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:863)
at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:841)
at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
at java.base/java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:2147)
at org.apache.pulsar.client.admin.internal.http.AsyncHttpConnector.lambda$retryOperation$4(AsyncHttpConnector.java:296)
at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:863)
at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:841)
at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
at java.base/java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:2147)
at org.asynchttpclient.netty.NettyResponseFuture.loadContent(NettyResponseFuture.java:222)
at org.asynchttpclient.netty.NettyResponseFuture.done(NettyResponseFuture.java:257)
at org.asynchttpclient.netty.handler.AsyncHttpClientHandler.finishUpdate(AsyncHttpClientHandler.java:241)
at org.asynchttpclient.netty.handler.HttpHandler.handleChunk(HttpHandler.java:114)
at org.asynchttpclient.netty.handler.HttpHandler.handleRead(HttpHandler.java:143)
at org.asynchttpclient.netty.handler.AsyncHttpClientHandler.channelRead(AsyncHttpClientHandler.java:78)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: javax.ws.rs.ClientErrorException: HTTP 409 {"reason":"Cluster already exists"}
at org.glassfish.jersey.client.JerseyInvocation.createExceptionForFamily(JerseyInvocation.java:985)
at org.glassfish.jersey.client.JerseyInvocation.convertToException(JerseyInvocation.java:967)
at org.glassfish.jersey.client.JerseyInvocation.access$700(JerseyInvocation.java:82)
... 54 more
Caused by: [CIRCULAR REFERENCE: javax.ws.rs.ClientErrorException: HTTP 409 {"reason":"Cluster already exists"}]

```

### Are you willing to submit a PR?

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

Start with MultiTopicsReaderTest.setup at line 79 and the testMultiTopic method, then reproduce the failure from the linked CI run. Investigate why setup receives a "Cluster already exists" conflict; done means the test no longer fails for this setup conflict when the test is run.

Written by the indexing model from the issue text.