Update backup to newer version

Summary

Need to update our backup ci test to 14.0 in order to support further upgrades.

Otherwise migrations fail with:

== 20210622041846 FinalizePushEventPayloadsBigintConversion: migrating ========
rake aborted!
StandardError: An error has occurred, all later migrations canceled:

Expected batched background migration for the given configuration to be marked as 'finished', but it is 'active': {:job_class_name=>"CopyColumnUsingBackgroundMigrationJob", :table_name=>"push_event_payloads", :column_name=>"event_id", :job_arguments=>[["event_id"], ["event_id_convert_to_bigint"]]}

Finalize it manualy by running

	gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,push_event_payloads,event_id,'[["event_id"]\, ["event_id_convert_to_bigint"]]']

Seen here: https://gitlab.com/gitlab-org/charts/gitlab/-/pipelines/329124920/failures