Unnamed repository; edit this file 'description' to name the repository.
Auto merge of #153821 - Lars-Schumann:const-step, r=Mark-Simulacrum
constify `Step` trait and all of its `impl`ementations
constifying [Step](https://github.com/rust-lang/rust/issues/42168) trait and all of its implementations, with some friendly help from [const_cmp](https://github.com/rust-lang/rust/issues/143800)
