fix(unplugin): correct type for raw.ts

Author: zhiyuanzmj

packages/unplugin/src/raw.ts

@@ -1,2 +1,5 @@
 import { plugin } from './core/plugin'
-export default plugin
+import type { Options } from './types'
+import type { UnpluginFactoryOutput } from 'unplugin'
+
+export default plugin as unknown as UnpluginFactoryOutput<Options, false>