Fixed billing-floor fallback for terminating Mac minis

The controller’s schedule-deletion fallback for physical termination was unreachable because the predicate that detects Scaleway’s precondition-failed error only matched the generic *scw.ResponseError and missed the typed *scw.PreconditionFailedError that the SDK returns. The predicate now matches both shapes, so when Scaleway refuses to delete a Mac mini because it is still inside the Apple licensing billing floor, the controller correctly falls back to scheduling deletion for the floor boundary instead of retrying forever.