Use PEP 604 in types.pyi (#5553)

CONTRIBUTING.md

@@ -140,8 +140,6 @@ Accepted features that *cannot* yet be used in typeshed include:
 - [PEP 585](https://www.python.org/dev/peps/pep-0585/) (builtin
   generics): see [#4820](https://github.com/python/typeshed/issues/4820),
   mostly supported but bugs remain for a few specific cases
-- [PEP 604](https://www.python.org/dev/peps/pep-0604/) (Union
-  pipe operator): see [#4819](https://github.com/python/typeshed/issues/4819)
 - [PEP 612](https://www.python.org/dev/peps/pep-0612/) (ParamSpec):
   see [#4827](https://github.com/python/typeshed/issues/4827)
 - [PEP 613](https://www.python.org/dev/peps/pep-0613/) (TypeAlias):
@@ -154,6 +152,8 @@ Supported features include:
 - [PEP 589](https://www.python.org/dev/peps/pep-0589/) (TypedDict)
 - [PEP 647](https://www.python.org/dev/peps/pep-0647/) (TypeGuard):
   see [#5406](https://github.com/python/typeshed/issues/5406)
+- [PEP 604](https://www.python.org/dev/peps/pep-0604/) (Union
+  pipe operator): see [#4819](https://github.com/python/typeshed/issues/4819)
 
 Features from the `typing` module that are not present in all
 supported Python 3 versions must be imported from `typing_extensions`

stdlib/types.pyi

@@ -34,9 +34,9 @@ class _Cell:
     cell_contents: Any
 
 class FunctionType:
-    __closure__: Optional[Tuple[_Cell, ...]]
+    __closure__: Tuple[_Cell, ...] | None
     __code__: CodeType
-    __defaults__: Optional[Tuple[Any, ...]]
+    __defaults__: Tuple[Any, ...] | None
     __dict__: Dict[str, Any]
     __globals__: Dict[str, Any]
     __name__: str
@@ -47,12 +47,12 @@ class FunctionType:
         self,
         code: CodeType,
         globals: Dict[str, Any],
-        name: Optional[str] = ...,
-        argdefs: Optional[Tuple[object, ...]] = ...,
-        closure: Optional[Tuple[_Cell, ...]] = ...,
+        name: str | None = ...,
+        argdefs: Tuple[object, ...] | None = ...,
+        closure: Tuple[_Cell, ...] | None = ...,
     ) -> None: ...
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
-    def __get__(self, obj: Optional[object], type: Optional[type]) -> MethodType: ...
+    def __get__(self, obj: object | None, type: type | None) -> MethodType: ...
 
 LambdaType = FunctionType