Remove Jenkins from OCP Payload

Goal

Remove Jenkins from the OCP Payload.

Problem

• Jenkins images are "non-trival in size, impact experience around OCP payloads
• Security advisories cannot be handled once, but against all actively supported OCP releases, adding to response time for handling said advisories
• Some customers may now want to upgrade Jenkins as OCP upgrades (making this configurable is more ideal)

Why is this important

• This is an engineering motivated item to reduce costs so we have more cycles for strategic work
• Aside from the team itself, top level OCP architects want this to reduce the image size, improve general OCP upgrade experience
• Sends a mix message with respect to what is startegic CI/CI when Jenkins is baked into OCP, but Tekton/Pipelines is an add-on, day 2 install sort of thing

Dependencies (internal and external)

See epic linking - need alternative non payload image available to provide relatively seamless migration

Also, the EP for this is approved and merged at https://github.com/openshift/enhancements/blob/master/enhancements/builds/remove-jenkins-payload.md

Estimate (xs, s, m, l, xl, xxl):

Questions:

• in addition to needing the CPaaS Image available first, have we confirmed the "deprecate first, then remove" requirements?  Per grooming we've assigned rgormley@redhat.com the task https://issues.redhat.com/browse/JKNS-274 for tracking this down.  I will be reaching out to Ben Parees (he is currently on vacation) to confirm from an OCP staff engineer / architect perspective if his approval of https://github.com/openshift/enhancements/pull/841 is sufficient signoff from that end.

       PARTIAL ANSWER ^^:  confirmed with Ben Parees in https://coreos.slack.com/archives/C014MHHKUSF/p1646683621293839 that EP merging is currently sufficient OCP "technical leadership" approval.

Previous work

Customers

assuming none