Fix user registration e2e spec

ee/app/views/registrations/welcome/_button.html.haml

 - onboarding_issues_experiment_enabled = experiment_enabled?(:onboarding_issues)
 
-= button_tag class: %w[btn btn-success w-100] do
+= button_tag class: %w[btn btn-success w-100], data: { qa_selector: 'get_started_button' } do
   = in_subscription_flow? || in_trial_flow? || (onboarding_issues_experiment_enabled && !in_invitation_flow? && !in_oauth_flow?) ? _('Continue') : _('Get started!')

qa/qa/page/main/sign_up.rb

@@ -14,6 +14,10 @@ module QA
           element :new_user_accept_terms_checkbox
         end
 
+        view 'ee/app/views/registrations/welcome/_button.html.haml' do
+          element :get_started_button
+        end
+
         def sign_up!(user)
           fill_element :new_user_name_field, user.name
           fill_element :new_user_username_field, user.username
@@ -24,7 +28,9 @@ module QA
           check_element :new_user_accept_terms_checkbox if has_element?(:new_user_accept_terms_checkbox)
 
           signed_in = retry_until do
-            click_element :new_user_register_button
+            click_element :new_user_register_button if has_element?(:new_user_register_button)
+
+            click_element :get_started_button if has_element?(:get_started_button)
 
             Page::Main::Menu.perform(&:has_personal_area?)
           end