fix: Move up the #_busy flag to fix the synchronization queue error.

[floatcat]

  #run() {
    if (this.#completed !== this.#total) {
      if (!this.#_paused && this.#running < this.#_concurrency) {
        const difference = this.#_concurrency - this.#running;

        const tasks = this.#_pending.removeRange(0, difference) as Tasks<T>;

        tasks.forEach((task) => {
          task.status = TaskStatus.RUNNING;

          this.#_running.add(task);

          task.run(this.#done(task)); // will call the #run and set #_busy at first

          /* istanbul ignore next */
          this.#runHook(RunnerEvents.RUN, {
            task,
          });
        });

        this.#_busy = true; // is too late
      }
.......

Move up the #_busy flag can fix the synchronization queue error.