fix: add workaround to fix build-temp-types on Netlify

[fwouts]

Description

This fixes an issue that occurs in the Netlify build, as reported by @patak-dev in #6856 (comment)

This is caused by postcss-load-config missing postcss as a peer dependency, causing a crash when running tsc since it cannot find the corresponding type definitions because of pnpm's strictness. Thank you @bluwy for the idea!

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[fwouts]

I can also send a PR for postcss-load-config but I won't have time for a couple of days at least (FYI @ai).

[bluwy]

Neat workaround!

[ai]

postcss-load-config is using postcss only in types https://github.com/postcss/postcss-load-config/blob/main/src/index.d.ts#L4=

Not in the code.

[patak-dev]

@fwouts thanks for the PR, I can confirm that this fixed the issue in Netlify

[bluwy]

@ai Vite bundles the types too so it needs to be a peer dep to be bundled properly. Maybe that's out of scope for the package, but I think it's fair to still add an optional peer dep for it so there's an explicit link instead on relying on hoisted types. It could help postcss-load-config too if there are changes to postcss's types.

[ai]

Optional peer is a good option. Send PR when you will have time.