Marking error-handling Side Exercise Deprecated

Per discussions on [issue 1780](#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.

Author: BethanyG

config.json

@@ -1284,7 +1284,8 @@
       "difficulty": 3,
       "topics": [
         "exception_handling"
-      ]
+      ], 
+      "deprecated": true
     },
     {
       "slug": "dominoes",