Upgrade Ansible runner to use Ansible 2.15.

Workaround

Use outdated collections with the current Ansible Spacelift runner

Problem

Many of the newer versions of Ansible collections require Ansible 2.15 or higher and throw errors when using 2.14. This means that any new features on those newer collections cannot be used and users who want to run their Ansible stacks in Spacelift have to code for the older collections.