$rerank aggregation stage for Native Reranking in Atlas.
Requires MongoDB 8.3+ and Native Reranking enabled via Atlas Project Settings. Best used after a $search, $vectorSearch, $rankFusion, or $scoreFusion stage.
Will migrate to pymongo_search_utils once available there. (PYTHON-5876)
Number of documents to pass to the reranker (max 1000)
Voyage AI reranking model (e.g. "rerank-2.5", "rerank-2", "rerank-2.5-lite"). Omit to use the latest available model.
