🤔 [QUESTION]旭日图图例无法配置？

### 🐛 Question description [Please make everyone to understand it]

### 💻 Link to minimal reproduction

Please provide a link by forking these links [g2plot](https://codesandbox.io/s/g2plot-reproduction-template-gyej1) or GitHub repo. What is a minimal reproduction, and why is it required?

### 🏞 Expected result

### 🚑 Any additional [like screenshots]

* **G2Plot Version**:
* **Platform**:

The issue concerns configuring the legend for a sunburst chart, but it includes no reproduction, expected result, version, platform, file, or test reference. First obtain a minimal reproduction and clarify the desired legend behavior; only then locate the sunburst legend configuration and define a testable fix.

Written by the indexing model from the issue text.