Merge branch '217941-ignore-updated-at-in-audit-events' into 'master'

Ignore update_at column in audit_events table

See merge request gitlab-org/gitlab!34156

app/models/audit_event.rb

@@ -2,6 +2,9 @@
 
 class AuditEvent < ApplicationRecord
   include CreatedAtFilterable
+  include IgnorableColumns
+
+  ignore_column :updated_at, remove_with: '13.3', remove_after: '2020-08-22'
 
   serialize :details, Hash # rubocop:disable Cop/ActiveRecordSerialize