fix(MuyangDog): 修复格挡计数器逻辑错误

将parryCounter.start()判断改为parryCounter.isCooldowned()，并在成功格挡后启动计数器

scripts/Contents/Characters/MuyangDog.gd

@@ -4,8 +4,9 @@ var parryCounter: CooldownTimer = CooldownTimer.new(3000)
 
 func ai():
 	super.ai()
-	if parryCounter.start():
+	if parryCounter.isCooldowned():
 		var track = getTrackingAnchor()
 		var bullet = BulletTool.findClosetBulletCanDamage(track, get_tree(), self , 400)
 		if is_instance_valid(bullet):
 			BulletBase.generate(ComponentManager.getBullet("Parrier"), self , track, track.angle_to_point(bullet.position))
+			parryCounter.start()