[PEP 696] Assigning to type variables with defaults gives unexpected results #19444

class Foo[X, Y = object]:
    def test(self) -> None:
        reveal_type(Foo[Y, X]())  # Foo[X`1, X`1]

class Bar[X = object, Y = object]:
    def test(self) -> None:
        reveal_type(Bar[Y, X]())  # Bar[Y`2 = builtins.object, Y`2 = builtins.object]