自定义tooltips无法使用

- [ ] I have searched the [issues](https://github.com/antvis/f2/issues) of this repository and believe that this is not a duplicate.

### Reproduction link
[https://f2.antv.antgroup.com/examples/area/area/#gradient](https://f2.antv.antgroup.com/examples/area/area/#gradient)

### Steps to reproduce
最新版可复现，官网demo也可复现，随便在一个面积图加
测试自定义tip}/>
就报错了，还有什么方式能自定义Tooltip内容？

| Environment | Info |
|---|---|
| f2 | 5.0.25 |
| System | - |
| Browser | - |

Start with the linked area/gradient reproduction using F2 5.0.25, then add the shown Tooltip component with showCrosshairs and customText to confirm the error. Investigate the Tooltip custom-content behavior and determine a supported way to render the requested text without an error; done means the reproduction works with custom tooltip content.

Written by the indexing model from the issue text.