[Bug Report] button component the type attribute is placed in the size attribute will take effect

### Element UI version
2.15.1

### OS/Browsers version
chrome 89

### Vue version
2.6.12

### Reproduction Link
https://codesandbox.io/s/gifted-keller-3so5q?file=/src/App.vue

### Steps to reproduce
```js
button
```

### What is Expected?
Element SyntaxError

### What is actually happening?
not error