Function spawn_with_options 

pub fn spawn_with_options<T: Actor + 'static>(
    args: T::Args,
    opts: SpawnOptions,
) -> (ActorRef<T>, JoinHandle<ActorResult<T>>)

Spawns a new actor with the given SpawnOptions and returns an ActorRef<T> along with a JoinHandle.

This is the most general spawn entry point. Use it when you need to enable the priority channel via SpawnOptions::with_priority or configure both mailbox capacity and priority in a single call.