[Enterprise Search] Fix failing snapshop tests (#149864)

## Summary

This fixes a few snapshot tests that were failing locally due to
timezone differences. Running tests locally now uses the same UTC
timezone that's used in CI.

x-pack/plugins/enterprise_search/jest.sh

@@ -25,4 +25,4 @@ fi
 # @see https://jestjs.io/docs/en/cli#options
 ARGS="${*:2}"
 
-yarn test:jest $TARGET $ARGS
+TZ="Etc/UTC" yarn test:jest $TARGET $ARGS

x-pack/plugins/enterprise_search/public/applications/shared/cron_editor/cron_editor.test.tsx

@@ -17,9 +17,7 @@ import { CronEditor } from './cron_editor';
 
 describe('CronEditor', () => {
   ['MINUTE', 'HOUR', 'DAY', 'WEEK', 'MONTH', 'YEAR'].forEach((unit) => {
-    // Skipped during Jest 29 upgrade
-    // No snapshot has been committed
-    test.skip(`is rendered with a ${unit} frequency`, () => {
+    it(`is rendered with a ${unit} frequency`, () => {
       const component = mountWithI18nProvider(
         <CronEditor
           fieldToPreferredValueMap={{}}