Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Minor upstream change, our README is completely different.
  Kept ours.
- `lib/tasks/assets.rake`:
  glitch-soc has extra code to deal with its theming system,
  upstream changed a line that exists in glitch-soc.
  Applied upstream changes.

app/serializers/rest/account_serializer.rb

@@ -129,10 +129,10 @@ class REST::AccountSerializer < ActiveModel::Serializer
   end
 
   def roles
-    if object.suspended?
+    if object.suspended? || object.user.nil?
       []
     else
-      [object.user.role].compact.filter { |role| role.highlighted? }
+      [object.user.role].compact.filter(&:highlighted?)
     end
   end