Flaky-test: PulsarFunctionTlsTest "Leader not yet ready"

### 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/11120172357/job/30897034288?pr=23327#step:11:1154

### Exception stacktrace

```
org.apache.pulsar.client.admin.PulsarAdminException: javax.ws.rs.ServiceUnavailableException: HTTP 503 {"reason":"Leader not yet ready. Please retry again"}
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.FunctionsImpl.createFunctionWithUrl(FunctionsImpl.java:199)
at org.apache.pulsar.functions.worker.PulsarFunctionTlsTest.testFunctionsCreation(PulsarFunctionTlsTest.java:274)
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.InvokeMethodRunnable.runOne(InvokeMethodRunnable.java:47)
at org.testng.internal.invokers.InvokeMethodRunnable.call(InvokeMethodRunnable.java:76)
at org.testng.internal.invokers.InvokeMethodRunnable.call(InvokeMethodRunnable.java:11)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)
```

```
2024-10-01T07:10:59,801 - INFO - [pulsar-external-listener-3425-1:WorkerUtils] - Encountered exception while at creating exclusive producer to topic persistent://public/functions/assignment
java.util.concurrent.ExecutionException: org.apache.pulsar.client.api.PulsarClientException$ProducerFencedException: {"errorMsg":"org.apache.pulsar.broker.service.BrokerServiceException$ProducerFencedException: Topic has an existing exclusive producer: c-my-cluster-fw-localhost-46303-scheduler-manager","reqId":2002931073644165119, "remote":"localhost/127.0.0.1:43319", "local":"/127.0.0.1:34620"}
at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:396) ~[?:?]
at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2096) ~[?:?]
at org.apache.pulsar.functions.worker.WorkerUtils.createExclusiveProducerWithRetry(WorkerUtils.java:409) ~[pulsar-functions-worker-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]
at org.apache.pulsar.functions.worker.SchedulerManager.acquireExclusiveWrite(SchedulerManager.java:171) ~[pulsar-functions-worker-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]
at org.apache.pulsar.functions.worker.LeaderService.becameActive(LeaderService.java:112) ~[pulsar-functions-worker-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]
at org.apache.pulsar.client.impl.ConsumerImpl.lambda$activeConsumerChanged$31(ConsumerImpl.java:1201) ~[pulsar-client-original-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.113.Final.jar:4.1.113.Final]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
Caused by: org.apache.pulsar.client.api.PulsarClientException$ProducerFencedException: {"errorMsg":"org.apache.pulsar.broker.service.BrokerServiceException$ProducerFencedException: Topic has an existing exclusive producer: c-my-cluster-fw-localhost-46303-scheduler-manager","reqId":2002931073644165119, "remote":"localhost/127.0.0.1:43319", "local":"/127.0.0.1:34620"}
```

full log output: https://gist.github.com/lhotari/bdd307df2e28331e033d0fe4f30ca5f0

### Are you willing to submit a PR?

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

Start with PulsarFunctionTlsTest.testFunctionsCreation at line 274 and trace the failure through FunctionsImpl.createFunctionWithUrl. Then inspect WorkerUtils.createExclusiveProducerWithRetry, SchedulerManager.acquireExclusiveWrite, and LeaderService.becameActive for the leader-readiness and producer-fencing interaction. Run the affected PulsarFunctionTlsTest and confirm it no longer fails with HTTP 503 while the worker is becoming ready.

Written by the indexing model from the issue text.