Add max_note_length and max_display_name_length to configuration.accounts in Instance entity (#37991)

app/serializers/rest/instance_serializer.rb

@@ -69,6 +69,8 @@ class REST::InstanceSerializer < ActiveModel::Serializer
       },
 
       accounts: {
+        max_display_name_length: Account::DISPLAY_NAME_LENGTH_LIMIT,
+        max_note_length: Account::NOTE_LENGTH_LIMIT,
         max_featured_tags: FeaturedTag::LIMIT,
         max_pinned_statuses: StatusPinValidator::PIN_LIMIT,
         max_profile_fields: Account::DEFAULT_FIELDS_SIZE,