chore(llm_node): remove unnecessary type ignore for context assignment (#10216)

api/core/workflow/nodes/llm/node.py

                     yield event
 
             if context:
-                node_inputs["#context#"] = context  # type: ignore
+                node_inputs["#context#"] = context
 
             # fetch model config
             model_instance, model_config = self._fetch_model_config(self.node_data.model)