我今天用1.18.1版本，不调用Done也可以跑完，这个是新版的改动原因吗？

// 输出调用chan接收到的参数
func doWorker(id int, w Worker) {
	for true {
		fmt.Printf("Worker %d received: %c\n", id, <-w.in)
		//w.done()
	}
}

type Worker struct {
	in   chan int
	done func()
}

// 创建好goroutine的并发方法，初始化Worker类的参数
func createWorker(id int, wg *sync.WaitGroup) Worker {
	w := Worker{
		in: make(chan int),
		done: func() {
			// 每一个完成后done一次
			wg.Done()
		},
	}
	go doWorker(id, w)

	return w
}

func main() {
	var works [10]Worker
	wg := sync.WaitGroup{}
	wg.Add(20)

	for i := 0; i < 10; i++ {
		works[i] = createWorker(i, &wg)
	}

	for i, work := range works {
		work.in <- 'a' + i
	}

	for i := 0; i < 10; i++ {
		works[i].in <- 'A' + i
	}
}