DEV: Add endpoint for dismissing outdated translations (#22509)

Recently we started giving admins a notice in the advice panel when their translations have become outdated due to changes in core. However, we didn't include any additional information.

This PR adds more information about the outdated translation inside the site text edit page, together with an option to dismiss the warning.

app/controllers/admin/site_texts_controller.rb

@@ -128,6 +128,26 @@ class Admin::SiteTextsController < Admin::AdminController
     render_serialized(site_text, SiteTextSerializer, root: "site_text", rest_serializer: true)
   end
 
+  def dismiss_outdated
+    locale = fetch_locale(params[:locale])
+    override = TranslationOverride.find_by(locale: locale, translation_key: params[:id])
+
+    raise Discourse::NotFound if override.blank?
+
+    if override.outdated?
+      override.update!(
+        status: "up_to_date",
+        original_translation:
+          I18n.overrides_disabled do
+            I18n.t(TranslationOverride.transform_pluralized_key(params[:id]), locale: :en)
+          end,
+      )
+      render json: success_json
+    else
+      render json: failed_json.merge(message: "Can only dismiss outdated translations"), status: 422
+    end
+  end
+
   def get_reseed_options
     render_json_dump(
       categories: SeedData::Categories.with_default_locale.reseed_options,