KeyboardInterrupt prints a traceback when other errors don't

In the recent logging changes, we tried to hide tracebacks by default to provide a cleaner UI experience in production.

However, when I hit `^C` to abort the test, I get a long ugly traceback in the console. This is particularly unhelpful since I don't usually need a traceback when I'm intentionally aborting the test.

I don't remember this being the behavior before, not sure how long it's been this way but seems unintentional.