fix: change Vite root, if test.root is used (#2637)

* fix: change Vite root, if test.root is used

* chore: cleanup

Author: sheremet-va

packages/vitest/src/node/plugins/index.ts

@@ -90,6 +90,7 @@ export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest('t
           open = '/'
 
         const config: ViteConfig = {
+          root: viteConfig.test?.root || options.root,
           esbuild: {
             sourcemap: 'external',