fix(define): allow define process.env

[bluwy]

Description

fix #15164

Allow define to override what process.env replaces, same as Vite 4. It works before because we replace things like this instead: https://github.com/vitejs/vite/pull/11151/files#diff-d90a7c21c9fb9222e557704bd906ea5671d5fe384c8fb105459eea8c36fdb4f0L22-R23

Additional context

Personally I don't think this is a good pattern in general, but I suppose it doesn't hurt to support it for now.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines, especially the Pull Request Guidelines.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Update the corresponding documentation if needed.
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

/ecosystem-ci run