Merge branch '322396-step-3-removal-of-unused-columns-in-elastic_reindexing_tasks' into 'master'

Remove ignore_columns from Elastic::ReindexingTask

See merge request gitlab-org/gitlab!71380

ee/app/models/elastic/reindexing_task.rb

 # frozen_string_literal: true
 
 class Elastic::ReindexingTask < ApplicationRecord
-  include IgnorableColumns
-
   self.table_name = 'elastic_reindexing_tasks'
 
   validates :max_slices_running, presence: true
   validates :slice_multiplier, presence: true
 
-  ignore_columns %i[documents_count index_name_from index_name_to elastic_task documents_count_target], remove_with: '14.3', remove_after: '2021-09-10'
-
   has_many :subtasks, class_name: 'Elastic::ReindexingSubtask', foreign_key: :elastic_reindexing_task_id
 
   enum state: {