Only include lint in future_incompatible lint group if not an edition lint
A follow up to #86330 - this only includes lints annotated with `FutureIncompatibleInfo` in the `future_incompatibile` lint group if the future compatibility is not tied to an edition.
We probably want to rename `FutureIncompatibleInfo` to something else since this type is now used to indicate future breakages of all kinds (even those that happen in editions). I'd prefer to do that in a separate PR though.
r? `@nikomatsakis`