In WT-9881 we're changing from a separate flush_tier API call to having it be a configuration parameter of checkpoint. The old flush_tier API was left in for now, returning ENOTSUP. That can be cleaned up later. Although several tests have tiered support added, none of them are run for PR or general testing.

However, some tickets like WT-9766 would be blocked from progressing until schema_abort is fixed to use the new API. This ticket is specifically to update schema_abort and unblock those tickets once WT-9881 is merged.