Merge branch '346327-remove-admin-services-js' into 'master'

Remove javascripts/pages/admin/services directory

See merge request gitlab-org/gitlab!75174

app/assets/javascripts/pages/admin/services/edit/index.js

-import IntegrationSettingsForm from '~/integrations/integration_settings_form';
-
-const integrationSettingsForm = new IntegrationSettingsForm('.js-integration-settings-form');
-integrationSettingsForm.init();

app/assets/javascripts/pages/admin/services/index/index.js

-import PersistentUserCallout from '~/persistent_user_callout';
-
-const callout = document.querySelector('.js-service-templates-deprecated');
-PersistentUserCallout.factory(callout);