Remove vitest import and use globals as per project convention

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>

Author: Copilot

packages/openapi-ts/src/config/output/__tests__/config.test.ts

@@ -2,8 +2,6 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 
-import { afterEach, beforeEach, describe, expect, it } from 'vitest';
-
 import { getOutput } from '../config';
 
 describe('getOutput', () => {