Fixes #38140 - Defer rebooting to "Power Action - Ansible Default" job

[hairmare]

What are the changes introduced in this pull request?

This defers the implementation of the reboot action to the "Power Action - Ansible Default" job template.

The current implementation exhibits the following bug on EL9:

ERROR! 'reboot' is not a valid attribute for a Play
The error appears to be in '/tmp/d20250115-157201-nu0y9u/project/playbook.yml': line 1, column 7, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
- reboot:
^ here

Considerations taken when implementing this change?

• I chose to use a render_template call so the code aligns with the rest of the existing template
• The other template used in the job is "Run Command - Ansible Default", i picked "Power Action - Ansible Default" because it seems to match

What are the testing steps for this pull request?

• Configure Foreman/Katello to use Ansible for all actions
• Install tracer on a host, apply an Errata that needs a reboot
• Schedule the reboot with the "Reboot host" button and watch the host reboot