Function wait_for_device_authorization 

pub async fn wait_for_device_authorization<H, C, X>(
    http: &H,
    clock: &C,
    authz: &DeviceAuthorization,
    cancel: &X,
) -> Result<String, CopilotAuthError>
where
    H: CopilotHttp,
    C: CopilotClock,
    X: CopilotCancel + ?Sized,

Poll until authorized, denied, expired, cancelled, or deadline.

Sleeps are cancellable: cancel is checked before each wait and during the wait via CopilotClock::sleep_cancellable.