chore(create-vite): use Type assertion in preact-ts (#8579)

Author: jsdayuan

packages/create-vite/template-preact-ts/src/main.tsx

@@ -2,4 +2,4 @@ import { render } from 'preact'
 import { App } from './app'
 import './index.css'
 
-render(<App />, document.getElementById('app')!)
+render(<App />, document.getElementById('app') as HTMLElement)