Big diff: Use new "|" union syntax (#5872)

stdlib/tkinter/dialog.pyi

@@ -1,10 +1,10 @@
 from tkinter import Widget
-from typing import Any, Mapping, Optional
+from typing import Any, Mapping
 
 DIALOG_ICON: str
 
 class Dialog(Widget):
     widgetName: str = ...
     num: int = ...
-    def __init__(self, master: Optional[Any] = ..., cnf: Mapping[str, Any] = ..., **kw) -> None: ...
+    def __init__(self, master: Any | None = ..., cnf: Mapping[str, Any] = ..., **kw) -> None: ...
     def destroy(self) -> None: ...