Change /api/v1/announcements to return regular Status entities (#26736)

app/serializers/rest/announcement_serializer.rb

@@ -9,7 +9,7 @@ class REST::AnnouncementSerializer < ActiveModel::Serializer
   attribute :read, if: :current_user?
 
   has_many :mentions
-  has_many :statuses
+  has_many :statuses, serializer: REST::StatusSerializer
   has_many :tags, serializer: REST::StatusSerializer::TagSerializer
   has_many :emojis, serializer: REST::CustomEmojiSerializer
   has_many :reactions, serializer: REST::ReactionSerializer
@@ -49,16 +49,4 @@ class REST::AnnouncementSerializer < ActiveModel::Serializer
       object.pretty_acct
     end
   end
-
-  class StatusSerializer < ActiveModel::Serializer
-    attributes :id, :url
-
-    def id
-      object.id.to_s
-    end
-
-    def url
-      ActivityPub::TagManager.instance.url_for(object)
-    end
-  end
 end