In an open expected class inheriting an expected interface, abstract
members are now inherited as _open_ fake overrides, not final. Final was
technically safer but also stricter and thus could be unexpected by the
user. In a final class, abstract members are still inherited as _final_
fake overrides. So, the general rule is now the following: the modality
of an expected fake override, which overrides only abstract members, in
a non-abstract class is equal to the modality of that class
#KT-22031 Fixed