Update langfuse/langchain/CallbackHandler.py

Co-authored-by: ellipsis-dev[bot] <65095814+ellipsis-dev[bot]@users.noreply.github.com>

Author: hassiebp

langfuse/langchain/CallbackHandler.py

@@ -57,7 +57,7 @@
 
 class LangchainCallbackHandler(LangchainBaseCallbackHandler):
     def __init__(
-        self, *, public_key: Optional[str] = None, update_trace: Optional[bool] = False
+        self, *, public_key: Optional[str] = None, update_trace: bool = False
     ) -> None:
         self.client = get_client(public_key=public_key)