fix benchmark typo

[czaloom]

Issue Description

results = {
            "number_of_datums": limit,
            "number_of_unique_labels": eval_.meta["labels"],
            "number_of_annotations": eval_.meta["labels"],  # this should be annotations
            "ingest_runtime": f"{(ingest_time):.1f} seconds",
            "eval_runtime": f"{(eval_.meta['duration']):.1f} seconds",
        }