fix(env): test NODE_ENV override before expand

[bluwy]

Description

fix #11302

Repro https://stackblitz.com/edit/vitejs-vite-ksgf5q?file=package.json&terminal=build (incorrect build warning)

If process.env.NODE_ENV is already set e.g. production, and there's a NODE_ENV=development in the .env file. dotenv-expand would override as NODE_ENV=production, making the NODE_ENV=development check fail.

This PR handles NODE_ENV before expand.

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• 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).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

/ecosystem-ci run

[vite-ecosystem-ci]

📝 Ran ecosystem CI: Open

suite	result
astro	✅ success
histoire	✅ success
iles	✅ success
ladle	✅ success
laravel	✅ success
marko	✅ success
nuxt-framework	❌ failure
previewjs	✅ success
rakkas	✅ success
sveltekit	❌ failure
vite-plugin-ssr	✅ success
vite-plugin-react	✅ success
vite-plugin-react-swc	✅ success
vite-plugin-svelte	❌ failure
vite-plugin-vue	✅ success
vite-setup-catalogue	✅ success
vitepress	✅ success
vitest	❌ failure
windicss	✅ success

[bluwy]

Besides vite-plugin-svelte, the failing ones seem to have unrelated issue to this PR. I'm not sure why vite-plugin-svelte is failing though, might need help on that as I'll be away this week, but I don't think the changes here would've affected it from the top of my head.

[patak-dev]

@benmccann @dominikg would you check if we can include this PR in a patch?

[patak-dev]

/ecosystem-ci run

[vite-ecosystem-ci]

📝 Ran ecosystem CI: Open

suite	result
astro	✅ success
histoire	✅ success
iles	✅ success
ladle	✅ success
laravel	✅ success
marko	✅ success
nuxt-framework	✅ success
previewjs	✅ success
rakkas	✅ success
sveltekit	✅ success
vite-plugin-ssr	✅ success
vite-plugin-react	✅ success
vite-plugin-react-swc	✅ success
vite-plugin-svelte	✅ success
vite-plugin-vue	✅ success
vite-setup-catalogue	✅ success
vitepress	✅ success
vitest	✅ success
windicss	✅ success