[Bug] When the topic name is four-paragraph and the namespace does not exist, the topic can also be produced and consumed normally

### Search before asking

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

### Read release policy

- [X] I understand that unsupported versions don't get bug fixes. I will attempt to reproduce the issue on a supported version of Pulsar client and Pulsar broker.

### Version

pulsar:4.0.1
java-sdk:2.9.2

### Minimal reproduce step

Producer producer = myClient.newProducer().
topic("persistent://wzjtest-tenant/cluster/test-ns/topic").create();

### What did you expect to see?

Not found: Namespace not found

### What did you see instead?

Can produce and consume normally

### Anything else?

_No response_

### Are you willing to submit a PR?

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

Start by running the Java reproduction against Pulsar 4.0.1 with the four-paragraph topic name and nonexistent namespace. Compare the broker's behavior with the expected “Namespace not found” result; done means producing and consuming are rejected when the namespace does not exist.

Written by the indexing model from the issue text.