<ranges>: Remove redundant _HAS_CXX23 guards

[StephanTLavavej]

This removes redundant _HAS_CXX23 guards around _Compile_time_max_size specializations, for views that are already guarded for C++23.

Note that these changes are very low risk because the primary template for _Compile_time_max_size is guarded for C++23. If we attempted to specialize it in C++20 mode, we'd get instant errors:

STL/stl/inc/ranges

Lines 44 to 55 in e36ee6c

	#if _HAS_CXX23
	_EXPORT_STD template <range _Rng>
	using const_iterator_t = decltype(_RANGES cbegin(_STD declval<_Rng&>()));
	_EXPORT_STD template <range _Rng>
	using const_sentinel_t = decltype(_RANGES cend(_STD declval<_Rng&>()));
	_EXPORT_STD template <range _Rng>
	using range_const_reference_t = iter_const_reference_t<iterator_t<_Rng>>;
	template <range _Ty>
	constexpr auto _Compile_time_max_size = (numeric_limits<_Make_unsigned_like_t<range_difference_t<_Ty>>>::max)();

This also adds a couple of #endif comments; they aren't strictly necessary but they helped me ripgrep for the redundant guards.

Noticed while reviewing #4707.

[StephanTLavavej]

I'm speculatively mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.