test(coroutine): 更新 WaitForTask 测试以使用 TaskCompletionSource

- 将测试中的 Task.Run 替换为 TaskCompletionSource
- 确保测试初始状态检查的准确性
- 改进测试的可靠性和可预测性

GFramework.Core.Tests/coroutine/WaitForTaskTests.cs

@@ -21,8 +21,8 @@ public class WaitForTaskTests
     [Test]
     public void WaitForTask_Should_Not_Be_Done_Initially()
     {
-        var task = Task.Run(() => { });
+        var tcs = new TaskCompletionSource<object?>();
-        var wait = new WaitForTask(task);
+        var wait = new WaitForTask(tcs.Task);
 
         Assert.That(wait.IsDone, Is.False);
     }