build: migrate autoprefixer from CJS require to ES module import

vite.config.mts

@@ -2,6 +2,7 @@ import { fileURLToPath, URL } from 'node:url'
 
 import { defineConfig } from 'vite'
 import { imagetools } from 'vite-imagetools'
+import autoprefixer from 'autoprefixer'
 import vue from '@vitejs/plugin-vue'
 
 // https://vitejs.dev/config/
@@ -16,7 +17,7 @@ export default defineConfig({
   css: {
     devSourcemap: true,
     postcss: {
-      plugins: [require('autoprefixer')]
+      plugins: [autoprefixer({})]
     }
   }
 })