fix type hint for SerializationInfo.round_trip (pydantic/pydantic-core#1576)

Original-commit-hash: 6a455fb

Author: davidhewitt

python/pydantic_core/core_schema.py

@@ -149,6 +149,7 @@ def exclude_none(self) -> bool: ...
     @property
     def serialize_as_any(self) -> bool: ...
 
+    @property
     def round_trip(self) -> bool: ...
 
     def mode_is_json(self) -> bool: ...