test: remove color-mode stub

Author: danielroe

test/nuxt/setup.ts

@@ -25,7 +25,6 @@ export default defineConfig({
           name: 'nuxt',
           include: ['test/nuxt/**/*.{test,spec}.ts'],
           environment: 'nuxt',
-          setupFiles: ['./test/nuxt/setup.ts'],
           environmentOptions: {
             nuxt: {
               rootDir: fileURLToPath(new URL('.', import.meta.url)),