fix: add ts-ignore to first test import for playground compatibility

When the workshop is initially set up, the playground is set to the first
problem which may not have correct types yet, causing type errors in the
test file import.

Author: kentcdodds

exercises/01.classes/01.solution.class-basics/index.test.ts

@@ -1,5 +1,6 @@
 import assert from 'node:assert/strict'
 import { test } from 'node:test'
+// @ts-ignore - playground may not have correct types initially
 import * as solution from './index.ts'
 
 await test('Product class should be exported', () => {