[Bug Report] el-checkbox-button error

### Element UI version
2.15.7

### OS/Browsers version
Windows 10，Firefox 98.0.2

### Vue version
2.6.11

### Reproduction Link
https://codepen.io/jh-d/pen/zYpdqaN

### Steps to reproduce
官网文档，示例的“组件-Checkbox 多选框-按钮样式”，代码就是执行异常。报错：

[Vue warn]: Unknown custom element: - did you register the component correctly? For recursive components, make sure to provide the "name" option.

### What is Expected?
“组件-Checkbox 多选框-按钮样式”，能正常使用。

### What is actually happening?
文档示例代码，渲染即报错。