Merge commit '5b457961fc1189a71599dc6c06b3f159b195a455' into glitch-soc/merge-upstream

Conflicts:
- `config/initializers/content_security_policy.rb`:
  Upstream fixed an issue that was not present in glitch-soc.
  Kept our version.

app/serializers/activitypub/actor_serializer.rb

@@ -99,7 +99,7 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
   end
 
   def name
-    object.suspended? ? '' : object.display_name
+    object.suspended? ? object.username : (object.display_name.presence || object.username)
   end
 
   def summary