can not use .cjs config file

[CHOYSEN]

Describe the bug

can not use vite.config.cjs after using index.cjs as export

Reproduction

https://github.com/CHOYSEN/cjs

System Info

System:
    OS: Windows 10 10.0.19044
    CPU: (12) x64 12th Gen Intel(R) Core(TM) i5-12400
    Memory: 8.83 GB / 15.75 GB
  Binaries:
    Node: 16.13.1 - C:\Program Files\nodejs\node.EXE
    npm: 8.1.2 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (102.0.1245.39)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    vite: workspace:* => 3.0.0-alpha.9

Used Package Manager

pnpm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.