adopt async/await

[tomerd]

No description provided.

[kirilltitov]

BTW this simple extension worked for me perfectly :)

public extension LifecycleHandler {
    init(_ handler: @escaping () async throws -> Void) {
        self = LifecycleHandler { callback in
            detach {
                do {
                    try await handler()
                    callback(nil)
                } catch {
                    callback(error)
                }
            }
        }
    }
}

[tomerd]

closed via #99