fix: relax typing on _fn_result_to_body to allow Any (#212)

src/dbus_fast/service.py

@@ -504,7 +504,7 @@ def _msg_body_to_args(msg: Message) -> List[Any]:
 
     @staticmethod
     def _fn_result_to_body(
-        result: Optional[List[Any]],
+        result: Optional[Any],
         signature_tree: SignatureTree,
         replace_fds: bool = True,
     ) -> Tuple[List[Any], List[int]]: