Remove unnecessary stacktrace clipping

[rickschubert]

We used to have a feature where we clip the stacktraces so that our users always know which of their tests throws the error; we didn't want the stacktrace to point to mock-inspect internals. This was necessary in the past when we were still doing data evaluation inside mock-inspect.

As per previous pull requests, we have gotten rid of this internal data evaluation though and instead went for a model where the caller themself just gets the data about how the network request works and they can do whatever they want with it. Thus, we should remove this complicated stacktrace clipping and passing around.