Update i18n and fix test failure

locale/gitlab.pot

@@ -4718,6 +4718,9 @@ msgstr ""
 msgid "Assign reviewer(s)"
 msgstr ""
 
+msgid "Assign severity"
+msgstr ""
+
 msgid "Assign some issues to this milestone."
 msgstr ""
 

spec/features/alert_management/alert_details_spec.rb

@@ -60,7 +60,7 @@ RSpec.describe 'Alert details', :js do
 
         expect(alert_status).to have_content('Triggered')
 
-        find('.btn-link').click
+        find('.gl-button').click
         find('.gl-new-dropdown-item', text: 'Acknowledged').click
 
         wait_for_requests