swap inheritance order for typing.Sequence (#12869)

This matches the order at runtime.

Author: tungol

stdlib/typing.pyi

@@ -575,7 +575,7 @@ class Collection(Iterable[_T_co], Container[_T_co], Protocol[_T_co]):
     @abstractmethod
     def __len__(self) -> int: ...
 
-class Sequence(Collection[_T_co], Reversible[_T_co]):
+class Sequence(Reversible[_T_co], Collection[_T_co]):
     @overload
     @abstractmethod
     def __getitem__(self, index: int) -> _T_co: ...