Function process_claimed_task 

pub async fn process_claimed_task<Store, Task, Kind, LeaseExpiresFn, RetryDelayFn>(
    store: Store,
    task: Task,
    lease: TaskLease,
    shutdown_token: CancellationToken,
    config: ClaimedTaskExecutionConfig<LeaseExpiresFn, RetryDelayFn>,
) -> Result<TaskDispatchOutcome, Store::Error>
where
    Store: ClaimedTaskExecutionStore<Task, Kind> + 'static,
    Task: ExecutableTaskRecord<Kind> + Send + Sync + 'static,
    Kind: Copy + Display + Send + Sync + 'static,
    LeaseExpiresFn: Fn(DateTime<Utc>) -> DateTime<Utc> + Copy + Send + Sync + 'static,
    RetryDelayFn: Fn(i32) -> i64 + Copy + Send + Sync + 'static,

Runs one claimed task through heartbeat, processing, retry, and failure handling.