Fix return type

Author: thewhaleking

async_substrate_interface/async_substrate.py

@@ -2493,7 +2493,7 @@ async def runtime_call(
         method: str,
         params: Optional[Union[list, dict]] = None,
         block_hash: Optional[str] = None,
-    ) -> ScaleType:
+    ) -> ScaleObj:
         """
         Calls a runtime API method