Make the meta-runtime supported_ansible list configurable

[alisonlhart]

The meta-runtime rule's supported_ansible list is currently static and cannot be configured. There should be a configuration option available to override this list in case maintainers wish to continue supporting EoL versions of Ansible within their own collections (upstream).

For example, a collection maintainer may want their collection to work with Ansible 2.9, even though Ansible 2.9 is not supported upstream anymore.

Relates to #4144.