[fix][test][branch-3.0] Correct topic policy loading logic and improve related tests

[nodece]

Motivation

#24279 breaks the branch-3.0 CI.

Modifications

• Fixed testCheckPersistencePolicies to align with updated topic policy loading behavior.
• Fixed an issue where topic policies were incorrectly loaded when the load balancer had not yet started.
  • The fix approach is based on: [improve][broker] PIP-376: Make topic policies service pluggable #23319
• Move ExtensibleLoadManagerCloseTest test groups to flaky, which always fail.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[lhotari]

• Fixed pulsar-sql license.

I'm sorry I missed this. Thanks for fixing. I pushed this commit directly to branch-3.0 so that it doesn't mix the review. 2061f681

[nodece]

@lhotari You can directly push this pr to the branch-3.0, or use merge button.

[lhotari]

• Move ExtensibleLoadManagerCloseTest and ExtensibleLoadManagerImplTest test groups to flaky.

@nodece Do these tests ever pass or are they completely broken?

[lhotari]

@lhotari You can directly push this pr to the branch-3.0, or use merge button.

@nodece It makes sense to merge this PR. I just have one question about the tests that are moved to flaky group. In master branch they are also in the flaky group, however they pass in most cases.

[nodece]

• Move ExtensibleLoadManagerCloseTest and ExtensibleLoadManagerImplTest test groups to flaky.

@nodece Do these tests ever pass or are they completely broken?

Some tests have failed:

Error:  Failures: 
  Error:  org.apache.pulsar.broker.loadbalance.extensions.ExtensibleLoadManagerCloseTest.testCloseAfterLoadingBundles
  [INFO]   Run 1: PASS
  Error:    Run 2: ExtensibleLoadManagerCloseTest.testCloseAfterLoadingBundles:90 » PulsarAdmin java.lang.IllegalStateException: Client instance has been closed.
  [INFO] 
  Error:  org.apache.pulsar.broker.loadbalance.extensions.ExtensibleLoadManagerImplTest.testNamespaceOwnershipListener
  [INFO]   Run 1: PASS
  Error:    Run 2: ExtensibleLoadManagerImplTest.testNamespaceOwnershipListener:436 » ConditionTimeout Assertion condition defined as a org.apache.pulsar.broker.loadbalance.extensions.ExtensibleLoadManagerImplTest expected [1] but found [2] within 10 seconds.
  [INFO] 
  Error:  org.apache.pulsar.broker.loadbalance.extensions.ExtensibleLoadManagerImplTest.testRoleChange

I don't have time to handle the ExtensibleLoadManager test, because these test has been fixed by some feature, we should not cherry-pick feature to the branch-3.0, so like: #23301

[nodece]

Now, ExtensibleLoadManagerImplTest belongs to the broker test group.