TT-69 fix: refactor condition

Author: Guido Quezada

time_tracker_api/time_entries/time_entries_repository.py

@@ -181,7 +181,8 @@ def on_create(self, new_item_data: dict, event_context: EventContext):
 
     def on_update(self, updated_item_data: dict, event_context: EventContext):
         CosmosDBRepository.on_update(self, updated_item_data, event_context)
-        if not 'deleted' in updated_item_data:
+        is_update_to_delete = 'deleted' in updated_item_data
+        if not is_update_to_delete:
             self.validate_data(updated_item_data, event_context)
         self.replace_empty_value_per_none(updated_item_data)