[BB-4096] koa.2a -> koa.3

Created by: 0x29a

This PR updates Ocim to use opencraft-release/koa.3 branch for new instances and integration-koa.3 branch for integration tests.

JIRA tickets:

• BB-4096

Dependencies:

• https://github.com/open-craft/ansible-secrets/pull/264

Testing instructions:

Ensure that PR passed all CI pipeline checks.

Reviewers

• @janimo