Check for `@testing-library/jest-dom` doesn't guarantee it's safe to use as `setupFiles` in Vitest

This check doesn't guarantee that passing '@testing-library/jest-dom/vitest' as setupFiles to Vitest is safe.

The current check:

https://github.com/solidjs/vite-plugin-solid/blob/904b25b6b846a20549281e576947cf5fbb5d55ba/src/index.ts#L182-L191

only verifies that eslint-plugin-solid itself can resolve @testing-library/jest-dom/vitest.
It does not guarantee that Vitest can safely use it as a setupFiles entry.

Problem

In my project (using pnpm), I hit a false positive:

• storybook depends directly on @testing-library/jest-dom.
• storybook-solidjs-vite depends on vite-plugin-solid
• vite-plugin-solid lists @testing-library/jest-dom as an optional peer dependency.
• Because of pnpm’s virtual store, both end up colocated such that require.resolve("@testing-library/jest-dom/vitest") from vite-plugin-solid succeeds.

However, my project itself doesn’t depend on @testing-library/jest-dom, since I only use Vitest with vite-plugin-solid for reactivity tests (no DOM tests).

When Vitest parses the config, it can resolve vite-plugin-solid, but it cannot resolve the automatically added @testing-library/jest-dom/vitest import. This breaks the setup.

Minimal Reproduction

1. Create an empty project

pnpm init
pnpm add -D vitest vite vite-plugin-solid

2. Add a vitest.config.js with

export default defineConfig({
  plugins: [solid()],
  test: {
    environment: "node",
  },
});

And a simple test file (it should run).

3. Reinstall dependencies, this time with a transitive dependency on @testing-library/jest-dom:

pnpm add -D storybook storybook-solidjs-vite

5. Run the test, it should now fail with "Failed to load url .../@testing-library/jest-dom/vitest".

Start with src/index.ts around lines 182-191, then run the pnpm minimal reproduction with Vitest described in the issue. Compare behavior with and without the transitive storybook dependency, and verify that the empty Solid/Vitest project still runs when the package is not a direct dependency.