collection: Enforce minimum ansible version 2.12

[berndfinger]

Solves issue #507.

Note: We are using version 2.12 and not 2.14 to extend the range of possible control nodes to older releases (e.g. RHEL 8.6).

[sean-freeman]

Agree with move to Ansible Core 2.12 as minimum for executing (from controller host, e.g. laptop or AWX) the Ansible Roles in this Ansible Collection; this increment to a later Ansible Core release will not impact execution of the Ansible Role’s code on the target/managed hosts.

Note: This would impact usage of the Ansible Roles in this Ansible Collection, if an end-user were to log onto a target host and attempted to run an Ansible Playbook as a localhost execution (in a similar way to running a shell script) because this would require the target host itself to have Ansible Core 2.12+ which may not be available for the OS major.minor version if released prior to Q4-2021.

[rhmk]

LGTM