Vite 8.1 doesn't resolve `tsconfigPaths` in CSS @import directives

### Describe the bug

Until Vite 8.0.16, it was possible to define path aliases in `tsconfig.json`, e.g.

```json
{
  "include": [/* ... */],
  "compilerOptions": {
    "paths": {
      "@/*": ["./src/*"]
    }
  }
}
```

and with `resolve.tsconfigPaths === true`, this alias was replaced not just in imports in JS/TS files, but also in e.g. CSS files:

```css
@import "@/styles/main.css";
```

This unfortunately no longer works since Vite 8.1, because the `vite:css` plugin throws the error that `postcss` can't find the unresolved import.

<details>
<summary>IMO likely cause in the `vite:css` plugin</summary>
I spent some time debugging this issue for withastro/astro#17163, and it seems this broke due to the "No fallback to the outermost tsconfig" change in Rolldown 1.1.2. I've tried every possible combination to ensure all files involved are included in the tsconfig, but nothing works.

I suspect it's because the Vite CSS module is not passing along the actual importer, but [instead passes](https://github.com/vitejs/vite/blob/dae9bb10cfc7acabaebadfcda82d16530ade748d/packages/vite/src/node/plugins/css.ts#L1562) `path.join(basedir, '*')` as the importer to the `resolve` function. This makes oxc-resolver think that the importer is not included in the tsconfig. After patching the CSS plugin to pass the path of the real importer instead, the build goes through as expected.
</details>

### Reproduction

https://github.com/TimonLukas/vite-8.1-tsconfig-paths-bug

### Steps to reproduce

1. Clone repo
2. `pnpm i`
3. `pnpm build`

### System Info

```shell
System:
    OS: Linux 7.0 Fedora Linux 39 (Container Image)
    CPU: (16) x64 AMD Ryzen 7 7700X 8-Core Processor
    Memory: 52.09 GB / 62.43 GB
    Container: Yes
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.16.0 - ~/.asdf/installs/nodejs/24.16.0/bin/node
    Yarn: 4.9.2 - ~/.asdf/installs/nodejs/24.16.0/bin/yarn
    npm: 11.13.0 - ~/.asdf/plugins/nodejs/shims/npm
    pnpm: 11.8.0 - ~/.asdf/installs/nodejs/24.16.0/bin/pnpm
    bun: 1.3.5 - ~/.bun/bin/bun
  npmPackages:
    vite: ^8.1.0 => 8.1.0
```

### Used Package Manager

npm

### Logs

<details>
<summary>Click to expand!</summary>

```shell
> pnpm build      
$ tsc && vite build
vite v8.1.0 building client environment for production...
Unable to resolve `@import "@/styles/imported.css"` from /path/to/vite-8.1-tsconfig-paths-bug/src/styles
✓ 8 modules transformed.
✗ Build failed in 26ms
error during build:
Build failed with 1 error:

[plugin vite:css] /path/to/vite-8.1-tsconfig-paths-bug/src/styles/main.css:undefined:NaN
Error: [postcss] ENOENT: no such file or directory, open '@/styles/imported.css'
    at async open (node:internal/fs/promises:640:25)
    at async Object.readFile (node:internal/fs/promises:1287:14)
    at async Object.load (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/node.js:22151:17)
    at async loadImportContent (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/postcss-import.js:392:19)
    at async Promise.all (index 0)
    at async resolveImportId (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/postcss-import.js:378:20)
    at async parseStyles (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/postcss-import.js:331:4)
    at async Object.Once (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/postcss-import.js:455:20)
    at async LazyResult.runAsync (/path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/postcss@8.5.15/node_modules/postcss/lib/lazy-result.js:293:11)
    at async runPostCSS (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/node.js:22205:19)
    at aggregateBindingErrorsIntoJsError (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/rolldown@1.1.2/node_modules/rolldown/dist/shared/error-T-E9reEy.mjs:48:18)
    at unwrapBindingResult (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/rolldown@1.1.2/node_modules/rolldown/dist/shared/error-T-E9reEy.mjs:18:128)
    at #build (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/rolldown@1.1.2/node_modules/rolldown/dist/shared/rolldown-build-DDMH4mGm.mjs:3256:34)
    at async buildEnvironment (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/node.js:32575:66)
    at async Object.build (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/node.js:32997:19)
    at async Object.buildApp (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/chunks/node.js:32994:153)
    at async CAC.<anonymous> (file:///path/to/vite-8.1-tsconfig-paths-bug/node_modules/.pnpm/vite@8.1.0/node_modules/vite/dist/node/cli.js:777:3) {
  errors: [Getter/Setter]
}
[ELIFECYCLE] Command failed with exit code 1.
```
</details>

### Validations

- [x] Follow our [Code of Conduct](https://github.com/vitejs/.github/blob/main/CODE_OF_CONDUCT.md)
- [x] Read the [Contributing Guidelines](https://github.com/vitejs/vite/blob/main/CONTRIBUTING.md).
- [x] Read the [docs](https://vite.dev/guide).
- [x] Check that there isn't [already an issue](https://github.com/vitejs/vite/issues) that reports the same bug to avoid creating a duplicate.
- [x] Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to [vuejs/core](https://github.com/vuejs/core) instead.
- [x] Check that this is a concrete bug. For Q&A open a [GitHub Discussion](https://github.com/vitejs/vite/discussions) or join our [Discord Chat Server](https://chat.vite.dev/).
- [x] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.

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Vite 8.1 doesn't resolve `tsconfigPaths` in CSS @import directives #22766

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Vite 8.1 doesn't resolve tsconfigPaths in CSS @import directives #22766

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Vite 8.1 doesn't resolve `tsconfigPaths` in CSS @import directives #22766