test: add timeout to vite re-use cache

Add timeout to wait for FS to stablize

(cherry picked from commit e615de7)

tests/legacy-cli/e2e/tests/vite/reuse-dep-optimization-cache.ts

@@ -1,3 +1,4 @@
+import { setTimeout } from 'node:timers/promises';
 import assert from 'node:assert';
 import { findFreePort } from '../../utils/network';
 import { execAndWaitForOutputToMatch, killAllProcesses, ng } from '../../utils/process';
@@ -28,6 +29,9 @@ export default async function () {
     const response = await fetch(`http://localhost:${port}/@vite/client`);
     assert(response.ok, `Expected 'response.ok' to be 'true'.`);
 
+    // Wait for vite to write to FS and stablize.
+    await setTimeout(2_000);
+
     // Terminate the dev-server
     await killAllProcesses();