Remove unnecessary UserNamespace TODOs

app/models/namespace.rb

@@ -51,9 +51,7 @@ class Namespace < ApplicationRecord
 
   # This should _not_ be `inverse_of: :namespace`, because that would also set
   # `user.namespace` when this user creates a group with themselves as `owner`.
-  # TODO: can this be moved into the UserNamespace class?
-  #       evaluate in issue https://gitlab.com/gitlab-org/gitlab/-/issues/341070
-  belongs_to :owner, class_name: "User"
+  belongs_to :owner, class_name: 'User'
 
   belongs_to :parent, class_name: "Namespace"
   has_many :children, -> { where(type: Group.sti_name) }, class_name: "Namespace", foreign_key: :parent_id

app/models/namespaces/user_namespace.rb

 # frozen_string_literal: true
 
-# TODO: currently not created/mapped in the database, will be done in another issue
-#       https://gitlab.com/gitlab-org/gitlab/-/issues/341070
 module Namespaces
   ####################################################################
   # PLEASE DO NOT OVERRIDE METHODS IN THIS CLASS!

spec/factories/namespaces.rb

@@ -5,8 +5,6 @@ FactoryBot.define do
     sequence(:name) { |n| "namespace#{n}" }
     path { name.downcase.gsub(/\s/, '_') }
 
-    # TODO: can this be moved into the :user_namespace factory?
-    #       evaluate in issue https://gitlab.com/gitlab-org/gitlab/-/issues/341070
     owner { association(:user, strategy: :build, namespace: instance, username: path) }
 
     trait :with_aggregation_schedule do