fix(dev): cache PostCSS for side-effect imports

[markdalgleish]

This PR centralises the caching logic introduced in #6505 and adapts the CSS side-effect import plugin to make use of it.

I've updated the HMR test to include a CSS side-effect import so that caching bugs get picked up. I've also added a PostCSS config to the deterministic build output test to ensure paths are handled correctly when using PostCSS.

[changeset-bot]

🦋 Changeset detected

Latest commit: 59cc10f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 18 packages

Name	Type
@remix-run/dev	Patch
create-remix	Patch
remix	Patch
@remix-run/architect	Patch
@remix-run/cloudflare	Patch
@remix-run/cloudflare-pages	Patch
@remix-run/cloudflare-workers	Patch
@remix-run/css-bundle	Patch
@remix-run/deno	Patch
@remix-run/eslint-config	Patch
@remix-run/express	Patch
@remix-run/netlify	Patch
@remix-run/node	Patch
@remix-run/react	Patch
@remix-run/serve	Patch
@remix-run/server-runtime	Patch
@remix-run/testing	Patch
@remix-run/vercel	Patch

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[github-actions]

🤖 Hello there,

We just published version v0.0.0-nightly-eb06147-20230614 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

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[github-actions]

🤖 Hello there,

We just published version 1.17.1-pre.1 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version v0.0.0-nightly-ad9adee-20230615 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version v0.0.0-nightly-12440f3-20230616 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 1.18.0-pre.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 1.18.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!