fix(css): always use css module content

[sapphi-red]

Description

Unfortunately I failed to implement what I said at #8900 and ended up reverting #7591 (review). 😞

This will cause the following code not to be tree-shaked.

/* input */
import './foo.module.css' // note that default export is not used

/* output(old) */
// none

/* output(new) */
var foo_module_css = { foo: 'foo_hash' }

But because this code usually does not happen, I think it is not so bad.

Also this PR does not fix #8245 (comment).

For better or worse, this PR could be backported to v2 since this is a simple partial revert of #7591. I'll create it later if we are going this way.

fixes #8245
fixes #8461
refs #8874, #8896

Additional context

The fix I said at #8900 is to resolve id before injecting ?used.
But this faced to some issues:

1. normalize.css will be normalize.css?used.
   • This is correct but the current vite resolver does not handle this case. Handling this case is very difficult and a lot of work will be needed. Previous attempt by other person: fix(vite): can not resolve node_module package which has a query surfix #8824 (comment)
2. #alias will be #alias?used.
   • This is not safe. #alias might be perfect matching like /^#alias$/. Replacing to #alias?used makes it not to be resolved.

We could use ${resolvedId}?used (/path/to/node_modules/normalize.css/normalize.css) instead. But if there is a exports field and normalize.css is not included, it will fail to resolve.

---

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.

[netlify]

✅ Deploy Preview for vite-docs-main canceled.

Name	Link
🔨 Latest commit	0af3e0c
🔍 Latest deploy log	https://app.netlify.com/sites/vite-docs-main/deploys/62c46e017d2d7e0009c33863