ActiveRecord::StatementInvalid: PG::QueryCanceled: ERROR: canceling statement due to statement timeout

https://sentry.gitlap.com/gitlab/gitlabcom/issues/42129/

PG::QueryCanceled: ERROR:  canceling statement due to statement timeout

  lib/gitlab/database.rb:100:in `bulk_insert'
    connection.execute <<-EOF
  lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits.rb:50:in `block in flush_buffers!'
    Gitlab::Database.bulk_insert('merge_request_diff_files', file_rows)
  lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits.rb:48:in `flush_buffers!'
    MergeRequestDiff.transaction do
  lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits.rb:31:in `block in perform'
    flush_buffers!
  lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits.rb:20:in `perform'
    merge_request_diffs.each do |merge_request_diff|
...
(55 additional frame(s) were not displayed)

ActiveRecord::StatementInvalid: PG::QueryCanceled: ERROR:  canceling statement due to statement timeout