wti_evict_app_assist_worker currently opens the history store to ensure we have cached history store cursor before performing eviction. Following this, we check whether eviction should proceed based on the eviction server existing and the cache meeting the percentage thresholds. This potentially means opening the history store unnecessarily and bailing from wti_evict_app_assist_worker because we didn't need to proceed with eviction anyway.

We should swap these checks so that we don't unnecessarily open the history store.

This specific case arose in WT-14376 during log replay.