Remove ignore columns concern from requirements

ee/app/models/requirements_management/requirement.rb

@@ -11,25 +11,8 @@ class Requirement < ApplicationRecord
     include AtomicInternalId
     include Sortable
     include Gitlab::SQL::Pattern
-    include IgnorableColumns
     include FilterableByTestReports
 
-    ignore_columns(
-      %i[
-        created_at
-        updated_at
-        author_id
-        cached_markdown_version
-        state
-        title
-        title_html
-        description
-        description_html
-      ],
-      remove_with: '16.9',
-      remove_after: '2024-01-22'
-    )
-
     # the expected name for this table is `requirements_management_requirements`,
     # but to avoid downtime and deployment issues `requirements` is still used
     # https://gitlab.com/gitlab-org/gitlab/-/merge_requests/30052#note_329556542