Updates ExpireJobCacheWorker to use replica as long as possible

What does this MR do?

The change is behind the load_balancing_for_expire_job_cache_worker feature toggle: #339137 (closed)

Note: idempotent! was removed because it is currently incompatible with LB (see #325291 (closed)). In other workers (see: !62073 (diffs) ) we left a comment to ensure that we bring back idempotent! once the issue is resolved, so I decided to follow that pattern.

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

#324378 (closed)