Fix docstring to mention 'rerank' method (#648)

Updated docstring to reflect the correct method exposed by the model.

Author: wirthual

libs/infinity_emb/infinity_emb/inference/batch_handler.py

@@ -191,7 +191,7 @@ async def rerank(
                 if top_n is None, <= 0 or out of range, all scores are returned
 
         Raises:
-            ModelNotDeployedError: If loaded model does not expose `embed`
+            ModelNotDeployedError: If loaded model does not expose `rerank`
                 capabilities
 
         Returns: