🤔 [QUESTION]用api去设置silder的状态，然后annomation不消失

### 🐛 Question description [Please make everyone to understand it]
我有两个折线图line1和line2，然后我想要line1的slider拖动变化之后，line2的slider也跟着line1一样变化，
目前根据文档只能用
` line2.update({
slider: {
start,
end
}
});`
的方式去设置line2的slider，但是我发现这样设置之后，line2的annomation都会消失。
### 💻 Link to minimal reproduction
https://codesandbox.io/s/g2plot-reproduction-template-forked-31isgt?file=/src/index.js

### 🏞 Expected result

### 🚑 Any additional [like screenshots]
可以有api直接设置line2的slider，然后line2的annomation都不消失
* **G2Plot Version**:
2.4.19
* **Platform**:
windows pc端

Start with the linked CodeSandbox reproduction at src/index.js, focusing on the two line charts, their sliders, and annotations. Reproduce the behavior in G2Plot 2.4.19 and inspect how line2.update changes the slider. Done means line2 follows line1's slider while its annotations remain visible.

Written by the indexing model from the issue text.