Update Node.py

I'm going to make small PRs whenever I find the error message confusing. Let me know if you would like me to change the wording on this.

src/nnsight/tracing/Node.py

@@ -385,7 +385,7 @@ def execute(self) -> None:
         except Exception as e:
 
             raise type(e)(
-                f"Above exception when execution Node: '{self.name}' in Graph: '{self.graph.id}'"
+                f"Above exception when executing Node: '{self.name}' in Graph: '{self.graph.id}'. Did you call `.output` instead of `.output()`?"
             ) from e
 
         finally: