v2 - We should NOT do sync over async

[baywet]

6 instances being suppressed

https://github.com/search?q=repo%3Amicrosoft%2FOpenAPI.NET%20VSTHRD002%20&type=code

This will cause poor performance and potential dead locks on backend services.

One of those instances is marked as obsolete, we should simply clean it up (and make a pass to ensure we remove any other obsolete API)

The five others were introduced with this preview. We should remove those methods, and let the consumer do the blocking if they absolutely need to with the proper patterns in terms of thread and context management