chore: prefer named exports (#8315)

* chore: prefer named exports

* chore: fix import

src/stepper/demo/index.vue

@@ -48,7 +48,7 @@
 <script lang="ts">
 import { reactive, toRefs } from 'vue';
 import { useTranslate } from '@demo/use-translate';
-import Toast from '../../toast';
+import { Toast } from '../../toast';
 
 const i18n = {
   'zh-CN': {

src/stepper/test/index.spec.ts

@@ -1,4 +1,4 @@
-import Stepper from '..';
+import { Stepper } from '..';
 import { mount, later } from '../../../test';
 
 test('should disable buttons and input when using disabled prop', () => {