Reset instance setting after test

Also retry clicking get started button until it does not exist

qa/qa/flow/sign_up.rb

@@ -15,16 +15,17 @@ module QA
             sign_up.fill_new_user_username_field(user.username)
             sign_up.fill_new_user_email_field(user.email)
             sign_up.fill_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 5
+
             sign_up.click_new_user_register_button
           end
 
-          # 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
-
           Page::Registration::Welcome.perform(&:click_get_started_button_if_available)
 
           if user.expect_fabrication_success

qa/qa/page/registration/welcome.rb

@@ -9,7 +9,12 @@ module QA
         end
 
         def click_get_started_button_if_available
-          click_element :get_started_button if has_element?(:get_started_button)
+          if has_element?(:get_started_button)
+            Support::Retrier.retry_until do
+              click_element :get_started_button
+              has_no_element?(:get_started_button)
+            end
+          end
         end
       end
     end

qa/qa/specs/features/browser_ui/1_manage/login/register_spec.rb

@@ -122,6 +122,7 @@ module QA
         end
 
         after do
+          set_require_admin_approval_after_user_signup_via_api(false)
           @user.remove_via_api! if @user
         end
       end