fix(vite): resolve tsconfig paths in CSS and JS resolvers (#19803)

Change `aliasOnly` from `true` to `false` when calling Vite's resolver
so that the full resolution pipeline runs, including the oxc resolver
responsible for tsconfig path resolution.

When `aliasOnly` was `true`, only the @rollup/plugin-alias plugin ran,
which meant `resolve.tsconfigPaths: true` had no effect on CSS `@import`
or JS `@plugin` resolution in `@tailwindcss/vite`.

Closes #19802.

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Co-authored-by: Robin Malfait <malfait.robin@gmail.com>