AtNoticebar speed 速度

**问题描述**
AtNoticebar speed 速度太快，调整无效

**复现步骤**
```
这是 NoticeBar 通告栏
```

**期望行为**
AtNoticebar 速度生效

**系统信息**

- Taro 版本 [Taro v3.5.11]
- Taro UI 版本 [^3.1.0-beta.4]
- 报错平台 [tt]

**补充信息**
抖音平台不生效
微信平台生效

Start by locating the AtNoticebar implementation in Taro UI and reproduce the example with speed={1} on the tt platform, then compare it with WeChat where it works. Trace the platform-specific speed behavior and verify that the requested speed takes effect on tt without breaking the existing WeChat behavior.

Written by the indexing model from the issue text.