Unconditionally-const supertraits are considered not dyn compatible
Let's save some space in the design of const traits by making `dyn Trait` where `trait Trait: const Super` not dyn compatible.
Such a trait cannot satisfy `dyn Trait: Trait`; we could in the future make this dyn compatible but *NOT* implement `Trait`, but that's a bit weird and seems like it needs to be independently justified moving forward.
Fixes https://github.com/rust-lang/rust/issues/145198
r? fee1-dead