perf(Weapons/SevenSoul): 减少七魂武器的攻击间隔时间

将七魂武器的攻击间隔从19500毫秒减少到15000毫秒，并添加5000毫秒的生成后延迟，以提升攻击流畅度和游戏体验

scripts/Contents/Weapons/SevenSoul.gd

@@ -6,7 +6,7 @@ func attack(entity: EntityBase):
 	for i in 6:
 		for j in BulletBase.generate(ComponentManager.getBullet("SevenSoul"), entity, entity.texture.global_position, 0):
 			j.index = i
-		await TickTool.millseconds(19500 / 6.0)
+		await TickTool.millseconds(15000 / 6.0)
 func update(to, origin, _entity):
 	origin["atk"] += 1 * to * soulLevel
 	return origin