Using SFC in markdown, styles in the `<style>` tag is not effect.

Describe the bug

when I bump vitepress to 1.0.0-rc.26, I found the styles in <style> were not included in the packaged product.

The style here is normal in the development environment, but it doesn't work after packing.

<template>
  <div class="box">Preview after packing, The text color is expected to be red</div>
</template>

<style>
.box {
  color: red;
}
</style>

I try downgraded to 1.0.0-rc.25, it was normal.

Reproduction

reproduction link:
https://stackblitz.com/edit/vite-xmetfv?file=docs%2FDemo.vue

Expected behavior

Packaged for preview and styles can also take effect

related documents:
https://vitepress.dev/guide/using-vue#script-and-style

System Info

System:
    OS: Linux 5.15 Ubuntu 22.04.2 LTS 22.04.2 LTS (Jammy Jellyfish)
    CPU: (16) x64 AMD Ryzen 7 4800H with Radeon Graphics
    Memory: 6.16 GB / 7.44 GB
    Container: Yes
    Shell: 5.1.16 - /bin/bash
  Binaries:
    Node: 18.18.2 - ~/.nvm/versions/node/v18.18.2/bin/node
    Yarn: 1.22.19 - /mnt/c/Program Files/nodejs/yarn
    npm: 9.8.1 - ~/.nvm/versions/node/v18.18.2/bin/npm
    pnpm: 8.10.5 - ~/.nvm/versions/node/v18.18.2/bin/pnpm
    bun: 1.0.12 - ~/.nvm/versions/node/v18.18.2/bin/bun
  npmPackages:
    vitepress: 1.0.0-rc.26 => 1.0.0-rc.26

Additional context

No response

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.