[skip ci] Add comment for newTaskScheduler (#9687)

Signed-off-by: Nxige-16 <xi.ge@zilliz.com>

internal/querycoord/task_scheduler.go

@@ -137,6 +137,7 @@ type TaskScheduler struct {
 	cancel context.CancelFunc
 }
 
+// NewTaskScheduler reloads tasks from kv and returns a new taskScheduler
 func NewTaskScheduler(ctx context.Context, meta Meta, cluster Cluster, kv *etcdkv.EtcdKV, rootCoord types.RootCoord, dataCoord types.DataCoord) (*TaskScheduler, error) {
 	ctx1, cancel := context.WithCancel(ctx)
 	taskChan := make(chan task, 1024)