Sleep before submiting registration form QA test

qa/qa/page/main/sign_up.rb

@@ -24,6 +24,14 @@ module QA
             fill_element :new_user_username_field, user.username
             fill_element :new_user_email_field, user.email
             fill_element :new_user_password_field, user.password
+
+            # Because invisible_captcha would prevent submitting this form
+            # within 4 seconds, sleep here. This can be removed once we
+            # implement invisible_captcha as an application setting instead
+            # of a feature flag, so we can turn it off while testing.
+            # Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/284113
+            sleep 4
+
             click_element :new_user_register_button if has_element?(:new_user_register_button)
             click_element :get_started_button if has_element?(:get_started_button)