Non async methods are being generated as async

[maca88]

Example:

public class NestedAssertThat
{
  public void Test()
  {
    Throws<NestedAssertThat>();
  }

  private void Throws<T>()
  {
    Assert.Throws<Exception>(
      () => new NestedClass().Build(), $"Test{typeof(T)}");
  }

  private class NestedClass
  {
    public void Build()
    {

    }
  }
}

Expected: None of the above methods should be generated

Actual: ThrowsAsync and TestAsync are generated