Make use of sshd's include directive now that OCP switched to 8.6+

#### Share the context

We reuse a "golden" sshd_config for all sshd kubernetes remediations because sshd didn't support include directives on RHEL8.

#### Description of problem:

Having a single sshd_config makes changing the config risky and makes it more difficult to follow "usptream" changes.

#### Proposed change:

Instead of a single sshd_config, let's create a file per remediation in an include directory

#### References:

1. The clusters need to be running https://access.redhat.com/errata/RHSA-2022:2013 so we probably still need the old file approach until <8.5 clusters go out of production
1.