How should we handle monkeypatching?

[njsmith]

@1st1 has strong feelings (I think) about monkeypatching being something that should be invoked explicitly instead of happening on import. I'm not sure of the concrete rationale in this particular case, where the monkeypatching has zero effect on the semantics of programs that don't use the library.

There is also potentially some complexity if we want to convince projects like sentry to start supporting this library out of the box, because they'll need to the tools to get their sys.excepthook patching and ours to play together properly.