tkinter.simpledialog.ask* functions can return None (#7219)

Author: matiuszka

stdlib/tkinter/simpledialog.pyi

@@ -22,6 +22,6 @@ class SimpleDialog:
     def wm_delete_window(self) -> None: ...
     def done(self, num: int) -> None: ...
 
-def askfloat(title: str | None, prompt: str, **kwargs: Any) -> float: ...
-def askinteger(title: str | None, prompt: str, **kwargs: Any) -> int: ...
-def askstring(title: str | None, prompt: str, **kwargs: Any) -> str: ...
+def askfloat(title: str | None, prompt: str, **kwargs: Any) -> float | None: ...
+def askinteger(title: str | None, prompt: str, **kwargs: Any) -> int | None: ...
+def askstring(title: str | None, prompt: str, **kwargs: Any) -> str | None: ...