fix cohere rerank provider (BerriAI#10822)

Author: keyute

litellm/utils.py

@@ -6489,7 +6489,10 @@ def get_provider_rerank_config(
         api_base: Optional[str],
         present_version_params: List[str],
     ) -> BaseRerankConfig:
-        if litellm.LlmProviders.COHERE == provider:
+        if (
+            litellm.LlmProviders.COHERE == provider
+            or litellm.LlmProviders.COHERE_CHAT == provider
+        ):
             if should_use_cohere_v1_client(api_base, present_version_params):
                 return litellm.CohereRerankConfig()
             else: