stdlib: Add defaults for positional-only parameters (#9655)

stdlib/_random.pyi

@@ -5,7 +5,7 @@ _State: TypeAlias = tuple[int, ...]
 
 class Random:
     def __init__(self, seed: object = ...) -> None: ...
-    def seed(self, __n: object = ...) -> None: ...
+    def seed(self, __n: object = None) -> None: ...
     def getstate(self) -> _State: ...
     def setstate(self, __state: _State) -> None: ...
     def random(self) -> float: ...