chore: clarify callback responsibility and remove redundant topic cleanup logic

[BackendArchitectX]

What changed

• Remove the redundant deleted-topic traversal from ElasticReplicaManager#asyncApplyDelta.
• Preserve callbacks for actual local partition deletion and partition state transitions.
• Document the callback's immediate per-partition notification responsibility.

Why

Global deleted-topic cleanup is already handled by BrokerMetadataPublisher#notifyGroupCoordinatorOfDeletedPartitions after asyncApplyDelta completes. The additional deletedTopicIds() traversal in ElasticReplicaManager therefore caused redundant cleanup notifications.

Fixes #2721

Testing

• :core:compileScala — passed
• :core:S3UnitTest --tests unit.kafka.server.streamaspect.ElasticReplicaManagerTest — passed

[BackendArchitectX]

Hi @superhx @Gezi-lzq @1sonofqiu, gentle ping on this PR when you have a chance.

I’ve kept the change tightly scoped to #2721: it removes only the redundant deleted-topic callback traversal, preserves callbacks for actual local partition deletion and state transitions, and leaves BrokerMetadataPublisher unchanged. I also added a regression test verifying that non-local partitions of a deleted topic no longer trigger the callback.

The branch is rebased on the latest main and CI is fully green. Happy to address any feedback.

[Gezi-lzq]

Thank you for your contribution. I will conduct a review this week!

[Gezi-lzq]

LGTM

[BackendArchitectX]

Thanks for the review @Gezi-lzq. Since the PR is approved and remains clean to merge, please let me know if anything else is needed from my side.

[BackendArchitectX]

Hi @Gezi-lzq

Just following up on #3542 when you have a chance.

Thank you again for reviewing and approving the PR. Since all checks are passing and the branch remains clean to merge would you be able to help with the final merge when convenient?

If anything further is needed from my side I’d be happy to address it.

Thank you for your time!

[BackendArchitectX]

Hi @Gezi-lzq,

Hope you're doing well! Thank you again for reviewing and approving PR #3542.

Since all checks are passing and the PR is ready to merge, I wanted to kindly check if there's anything further needed from my side or if you could help guide it toward merging.

Really appreciate your time and support!

[Gezi-lzq]

I've already approved it, can't you merge it here? @BackendArchitectX

[BackendArchitectX]

Hi @Gezi-lzq, thank you for approving the PR. I’m unable to merge it from my side because I don’t have the required permissions. Could you please help merge it or connect me with the maintainer who can? Thank you.