[Bug] windows下mako配置约定式路由build后，less样式丢失

[flgame]

What happens?

windows下使用umi4，开启mako及约定式路由build后，less样式丢失，通过浏览器debug，可以看到样式文件以base64格式打包进去了。
使用配置式路由是正常，npm start也正常，只有约定式路由下npm run build 会有问题。

import { defineConfig } from "umi";

export default defineConfig({
  //routes: [
  //  { path: "/", component: "index" },
  //  { path: "/docs", component: "docs" },
  //],
  npmClient: 'pnpm',
  mako: {},
  exportStatic: {},
});

Mini Showcase Repository(REQUIRED)

https://codesandbox.io/p/sandbox/7gljcr

How To Reproduce

Steps to reproduce the behavior: 1. 2.

Expected behavior 1. 2.

Context

• Umi Version: 4.4.5
• Node Version: 18
• Platform: windows

[flgame]

help @sorrycc