Interfaces in Go (the closest equivalent to traits in Rust) don't have to have methods either, but they are structurally typed. This is like "static duck typing" if you will. So an interface with no methods is implemented by every type in the language (indeed, this became such a useful pattern that the name "any" was reserved for it in Go 1.18).

Marker interfaces can exist in Go, but here they are another kind of hack. They must define at least one method (which doesn't have to be public), though that method is never actually meant to be called.