Enable pipeline archival on Gitlab.com

Background

With Extend job archival mechanism to the whole pipe... (#271614 - closed) we consolidate the archival concept to the whole pipeline (previously at job-level).

Problem

On Gitlab.com we don't have the archival period configured at instance level. This means that pipelines even years old could be retried or job played by users. We should enable this setting on Gitlab.com in order to maintain pipelines read-only after a period of time.

This helps aligning the data retention with pipeline archival to ensure pipelines are not modified after a period of time.

Proposal

Set pipeline archival period in the instance-settings. This would require us to file a Change Management Request with infrastructure.

What would the configured value be?

We may need to add instrumentation first for specific endpoints/actions to understand the age of pipelines that are retried/cancelled or job played, etc. Based on the observed data we could set a limit that is strict but not disruptive to customers.