resume original type.

Author: GdoongMathew

src/lightning/pytorch/utilities/model_helpers.py

@@ -115,7 +115,7 @@ def __init__(self, method: Callable[Concatenate[type[_T], _P], _R_co]) -> None:
         self.method = method
 
     @override
-    def __get__(self, instance: _T, cls: Optional[type[_T]] = None) -> Callable[_P, _R_co]:  # type: ignore[override]
+    def __get__(self, instance: Optional[_T], cls: Optional[type[_T]] = None) -> Callable[_P, _R_co]:  # type: ignore[override]
         # The wrapper ensures that the method can be inspected, but not called on an instance
         @functools.wraps(self.method)
         def wrapper(*args: Any, **kwargs: Any) -> _R_co: