Fix: support cross language for API. (#8946)

### What problem does this PR solve?

Close #8943

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

sdk/python/ragflow_sdk/ragflow.py

@@ -197,6 +197,7 @@ class RAGFlow:
         top_k=1024,
         rerank_id: str | None = None,
         keyword: bool = False,
+        cross_languages: list[str]|None = None
     ):
         if document_ids is None:
             document_ids = []
@@ -211,6 +212,7 @@ class RAGFlow:
             "question": question,
             "dataset_ids": dataset_ids,
             "document_ids": document_ids,
+            "cross_languages": cross_languages
         }
         # Send a POST request to the backend service (using requests library as an example, actual implementation may vary)
         res = self.post("/retrieval", json=data_json)