Removed sleep lib from test utils

- this is generally an anti-pattern in tests and leads to flaky
  behaviour when tests are ran on different machines/loads
- this is currently unused so it is an easy removal

ghost/core/test/e2e-api/admin/images.test.js

@@ -8,7 +8,6 @@ const urlUtils = require('../../../core/shared/url-utils');
 const imageTransform = require('@tryghost/image-transform');
 const sinon = require('sinon');
 const storage = require('../../../core/server/adapters/storage');
-const sleep = require('../../utils/sleep');
 const {anyErrorId} = matchers;
 const {imageSize} = require('../../../core/server/lib/image');
 const configUtils = require('../../utils/configUtils');

ghost/core/test/utils/e2e-framework.js

@@ -480,6 +480,5 @@ module.exports = {
     configUtils: require('./configUtils'),
     dbUtils: require('./db-utils'),
     urlUtils: require('./urlUtils'),
-    sleep: require('./sleep'),
     resetRateLimits
 };

ghost/core/test/utils/sleep.js

@@ -1,15 +0,0 @@
-/**
- * Adds artificial "sleep" time that can be awaited
- * In most cases where this module is used we are awaiting
- * for the async event processing to trigger/finish
- * 
- * Can probably be substituted by timerPromises in the future
- * ref.: https://nodejs.org/dist/latest-v18.x/docs/api/timers.html#timerspromisessettimeoutdelay-value-options
- * @param {number} ms
- * @returns {Promise<void>}
- */
-module.exports = ms => (
-    new Promise((resolve) => {
-        setTimeout(resolve, ms);
-    })
-);