Downgrade to community.general 8.6.9 for full Python 3.6 support

Version 9.x still has some modules (like redhat_subscription) that use
Python 3.7+ features (from __future__ import annotations), causing
failures on RHEL 8 with Python 3.6.

Version 8.6.9 is the latest 8.x release and fully supports Python 3.6.