Investigate why BuildQueueWorker is hitting primary

In #332586 (closed), we enabled the feature flag load_balancing_for_build_queue_worker , but we saw that there are still some reads from the primary.

Part of them was caused by #333421 (closed), but once we tried enabling the feature flag again, we have noticed that primary reads were still present.

We should investigate, what is causing some read queries to hit primary instead of replica