Marking `error-handling` Side Exercise Deprecated (#2281)
Marking `error-handling` Side Exercise Deprecated (#2281)

* Marking `error-handling` Side Exercise Deprecated 

Per discussions on [issue 1780](https://github.com/exercism/python/issues/1780), the `error-handling` exercise probably needs a full re-write.  Until that can be completed, we're deprecating the exercise for the Python track.

* Changed topics to null for deprecated exercise

* Changed unlock & difficulty params for error-handling

Exercise has be deprecated.

* remove trailing whitespace

Co-authored-by: Corey McCandless <2e99c65951ea377198e4c9cdc614b7672f5a4847@users.noreply.github.com>
exercism/python,exercism/python,jmluy/xpython,jmluy/xpython