Function run_with_seed 

pub fn run_with_seed<'t, F>(
    config: SchedulerConfig,
    seed: SchedSeed,
    setup: F,
) -> (RunOutcome, SchedTrace)
where
    F: FnOnce(&mut Scheduler<'t>),

Run setup (which spawns tasks and creates channels) under a fresh recording scheduler seeded by seed, returning the outcome and the scheduling trace.