[2025-06 LWG Motion 29] P3060R3 Add std::views::indices(n)

[jensmaurer]

https://wiki.edg.com/pub/Wg21sofia2025/StrawPolls/p3060r3.html

[jwakely]

The incoming paper says "if T models is-integer-like" however that's a variable template, so can't be modeled. I'll fix it.

[jwakely]

The paper also says that "customization point object" should have a cross-reference to [customization.point.object], however p1 in the same subclause already has that cross-reference. Do we need it there twice?