Fix crash with default computed property import in no-unused-services rule

[bmish]

Crash detected by:

• Fix setup for eslint-remote-tester for testing our rules against other repos #1741

Rule: "ember/no-unused-services"
Path: emberjs/data/@types/@ember/array/-private/enumerable.d.ts
Link: https://github.com/emberjs/data/blob/HEAD/@types/@ember/array/-private/enumerable.d.ts#L2

  1 | import type NativeArray from '@ember/array/-private/native-array';
> 2 | import type ComputedProperty from '@ember/object/computed';
  3 | import type Mixin from '@ember/object/mixin';
  4 | /**
  5 |  * This mixin defines the common interface implemented by enumerable objects

Error:
TypeError: Cannot read property 'name' of undefined
Occurred while linting /home/runner/work/eslint-plugin-ember/eslint-plugin-ember/node_modules/eslint-remote-tester/.cache-eslint-remote-tester/emberjs/data/@types/@ember/array/-private/enumerable.d.ts:2
Rule: "ember/no-unused-services"
    at ImportDeclaration (/home/runner/work/eslint-plugin-ember/eslint-plugin-ember/lib/rules/no-unused-services.js:133:40)