OrderedSet.reverse: Require key and reverse to be kwargs

Technically, this is a breaking change.
However, use as a positional argument was never supposed to be allowed in the first place.

Caught by flake8-boolean-trap via `ruff check`

Author: Techcable

src/techcable/orderedset/_orderedset.py

@@ -206,7 +206,7 @@ def __gt__(self, other: object) -> bool:
     def __ge__(self, other: object) -> bool:
         return self._impl_cmp_op(other, operator.ge)
 
-    def sort(self, key: Optional[Callable[[T], U]] = None, reverse: bool = False) -> None:
+    def sort(self, *, key: Callable[[T], U] | None = None, reverse: bool = False) -> None:
         """Sort the elements in the set, as if calling list.sort"""
         self._elements.sort(key=key, reverse=reverse)