Migrate from CommonJS to ESM (#6651)

services/github/github-issues-search.tester.js

@@ -1,12 +1,10 @@
-'use strict'
-
-const { isMetric } = require('../test-validators')
-const { ServiceTester } = require('../tester')
-const t = (module.exports = new ServiceTester({
+import { isMetric } from '../test-validators.js'
+import { ServiceTester } from '../tester.js'
+export const t = new ServiceTester({
   id: 'GithubIssuesSearch',
   title: 'Github Issues Search',
   pathPrefix: '/github',
-}))
+})
 
 t.create('GitHub issue search (valid query string)')
   .get(