Fix missing "not recommended" label on "Allow trends without review" (#20480)

app/views/admin/settings/discovery/show.html.haml

@@ -19,7 +19,7 @@
     = f.input :trends, as: :boolean, wrapper: :with_label
 
   .fields-group
-    = f.input :trendable_by_default, as: :boolean, wrapper: :with_label
+    = f.input :trendable_by_default, as: :boolean, wrapper: :with_label, recommended: :not_recommended
 
   %h4= t('admin.settings.discovery.public_timelines')