argparse.pyi: Allow Callable[[Text], _T] (#3013)

Fixes #2988

Author: utkarsh2102

stdlib/2and3/argparse.pyi

@@ -56,7 +56,7 @@ class _ActionsContainer:
                      nargs: Union[int, Text] = ...,
                      const: Any = ...,
                      default: Any = ...,
-                     type: Union[Callable[[str], _T], FileType] = ...,
+                     type: Union[Callable[[Text], _T], Callable[[str], _T], FileType] = ...,
                      choices: Iterable[_T] = ...,
                      required: bool = ...,
                      help: Optional[Text] = ...,
@@ -254,7 +254,7 @@ class Action(_AttributeHolder):
                  nargs: Optional[Union[int, Text]] = ...,
                  const: Any = ...,
                  default: Any = ...,
-                 type: Optional[Union[Callable[[str], _T], FileType]] = ...,
+                 type: Optional[Union[Callable[[Text], _T], Callable[[str], _T], FileType]] = ...,
                  choices: Optional[Iterable[_T]] = ...,
                  required: bool = ...,
                  help: Optional[Text] = ...,