Is there any "real" difference between `@MainActor @Sendable () -> ()` and `@MainActor () -> ()`

[sisoje (Lazar Otasevic)]

Seems like @Sendable has runtime presence.

Basically I can not cast a runtime object to @MainActor ()->() because compiler prevents me by converting it to @MainActor @Sendable ()->() and casting fails. That is an issue.