Function execute_jobs 

async fn execute_jobs<F, Fut>(
    count: usize,
    concurrency: usize,
    token: &CancellationToken,
    deadline: Option<Instant>,
    execute: F,
) -> (Accumulator, Duration, usize)
where
    F: Fn(usize) -> Fut + Send + Sync + 'static,
    Fut: Future<Output = Outcome> + Send + 'static,

Stop scheduling at the deadline; finish in-flight operations before returning.