Extend update and upgrade tasks to run up to step 5

[Carlos Goncalves]

Post update and upgrade tasks (post_update_tasks and post_upgrade_tasks, respectively) are capped at step 3.

- https://github.com/openstack/tripleo-heat-templates/blob/fa3140a7236eea8ac87a24c57ae93dcdd3880a0e/common/deploy-steps.j2#L23
- https://github.com/openstack/tripleo-heat-templates/blob/fa3140a7236eea8ac87a24c57ae93dcdd3880a0e/common/deploy-steps.j2#L26

There are use cases where a service has to run post update/upgrade tasks in step 5. For example, Octavia runs workflow tasks in step 5 and needs to be able to run post tasks afterward for cleanup. See https://review.opendev.org/#/q/I32524f85ef6a0ca3e87fa9acc8c9e12776225717

Related: https://bugzilla.redhat.com/show_bug.cgi?id=1776912

[Carlos Goncalves (cgoncalves)]

Octavia moved to external tasks in Rocky. Max external update and upgrade steps are similarly capped to step 2. We need to extend max steps to 5 as well.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/696106

[OpenStack Infra (hudson-openstack)]

Change abandoned by Carlos Goncalves (<email address hidden>) on branch: master
Review: https://review.opendev.org/696106
Reason: I still think this is a limitation in the update/upgrade framework but given that Octavia took a different path for update and upgrade (bits added to the deploy workflow), we no longer require this.