Expect relays to answer with accept/reject (#8179)

app/lib/activitypub/activity/accept.rb

@@ -11,6 +11,8 @@ class ActivityPub::Activity::Accept < ActivityPub::Activity
   private
 
   def accept_follow
+    return accept_follow_for_relay if relay_follow?
+
     target_account = account_from_uri(target_uri)
 
     return if target_account.nil? || !target_account.local?
@@ -19,6 +21,18 @@ class ActivityPub::Activity::Accept < ActivityPub::Activity
     follow_request&.authorize!
   end
 
+  def accept_follow_for_relay
+    relay.update!(state: :accepted)
+  end
+
+  def relay
+    @relay ||= Relay.find_by(follow_activity_id: object_uri)
+  end
+
+  def relay_follow?
+    relay.present?
+  end
+
   def target_uri
     @target_uri ||= value_or_id(@object['actor'])
   end