complete test suite conversions; simplify fn name

__tests__/external-config.test.ts

@@ -1,6 +1,6 @@
 import {expect, test, beforeEach} from '@jest/globals'
 import {readConfig} from '../src/config'
-import * as Utils from '../src/utils'
+import * as spdx from '../src/spdx'
 import {setInput, clearInputs} from './test-helpers'
 
 const externalConfig = `fail_on_severity: 'high'
@@ -25,10 +25,6 @@ jest.mock('octokit', () => {
   }
 })
 
-beforeAll(() => {
-  jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(true)
-})
-
 beforeEach(() => {
   clearInputs()
 })