fix(config): use file url for import path (fixes #9471)

[sapphi-red]

Description

I tested this PR with #9471.
Actually #9471 needs to change import { libConfig } from "../vite-config" into import { libConfig } from "../vite-config/index.js" because ESM doesn't support dir imports.

fixes #9471

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[bluwy]

I was just making this PR 🙃