Remove unnecessary handler instantiation in PySpringApplication's graceful shutdown initialization

Author: William-W-Chen

py_spring_core/core/application/py_spring_application.py

@@ -295,8 +295,7 @@ def __init_graceful_shutdown(self) -> None:
         handler_cls = self._init_external_handler(GracefulShutdownHandler)
         if handler_cls is None:
             return
-            
-        handler: GracefulShutdownHandler = handler_cls()
+        handler_cls()
         logger.debug(f"[{handler_type} INIT] Graceful shutdown initialized")
 
     def __configure_uvicorn_logging(self):