LWG-3563 `keys_view` example is broken

[StephanTLavavej]

LWG-3563 keys_view example is broken

STL/stl/inc/ranges

Lines 4711 to 4714 in 5e3574b

	template <class _Rng>
	using keys_view = elements_view<views::all_t<_Rng>, 0>;
	template <class _Rng>
	using values_view = elements_view<views::all_t<_Rng>, 1>;

[CaseyCarter]

The product update is trivial, and I don't think the test changes will be too bad, so tagging this good-first-issue.