Cleanup unneeded code

lib/gitlab/database/reindexing/reindex_concurrently.rb

@@ -5,8 +5,6 @@ module Gitlab
     module Reindexing
       # This is a >= PG12 reindexing strategy based on `REINDEX CONCURRENTLY`
       class ReindexConcurrently
-        include Gitlab::Utils::StrongMemoize
-
         ReindexError = Class.new(StandardError)
 
         TEMPORARY_INDEX_PATTERN = '\_ccnew[0-9]*'
@@ -45,7 +43,6 @@ module Gitlab
               execute("REINDEX INDEX CONCURRENTLY #{quote_table_name(index.schema)}.#{quote_table_name(index.name)}")
             end
           end
-
         ensure
           cleanup_dangling_indexes
         end

spec/lib/gitlab/database/reindexing/reindex_concurrently_spec.rb

@@ -109,32 +109,4 @@ RSpec.describe Gitlab::Database::Reindexing::ReindexConcurrently, '#perform' do
       end
     end
   end
-
-  def expect_index_rename(from, to)
-    expect(connection).to receive(:execute).with(<<~SQL).ordered
-      ALTER INDEX "public"."#{from}"
-      RENAME TO "#{to}"
-    SQL
-  end
-
-  def expect_index_drop(drop_index)
-    expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
-      expect(instance).to receive(:run).with(raise_on_exhaustion: false).and_yield
-    end
-
-    expect_to_execute_concurrently_in_order(drop_index)
-  end
-
-  def find_index_create_statement
-    ActiveRecord::Base.connection.select_value(<<~SQL)
-      SELECT indexdef
-      FROM pg_indexes
-      WHERE schemaname = 'public'
-      AND indexname = #{ActiveRecord::Base.connection.quote(index.name)}
-    SQL
-  end
-
-  def check_index_exists
-    expect(find_index_create_statement).to eq(original_index)
-  end
 end