ISTWCMS-4881: Only add CAPTCHA to empty Webforms

During migration, a new Webform may not be empty. Previously, migrated
Webforms would lose their elements.

uw_sites_all.module

@@ -133,7 +133,7 @@ function uw_sites_all_update_projects_alter(&$projects) {
  */
 function uw_sites_all_webform_presave(WebformInterface $webform): void {
   // Add a Webform CAPTCHA component to each newly-created Webform.
-  if ($webform->isNew()) {
+  if ($webform->isNew() && empty($webform->getElementsRaw())) {
     $elements = [
       'captcha' => [
         '#type' => 'captcha',