update to prevent INJECT_FACTS_AS_VARS deprecation

[mikevo-esd]

Fixes the deprecation warning below and alike. Usages were replaced accordingly.

TASK [geerlingguy.apache : Include OS-specific variables.] *********************
[WARNING]: Deprecation warnings can be disabled by setting `deprecation_warnings=False` in ansible.cfg.
[DEPRECATION WARNING]: INJECT_FACTS_AS_VARS default to `True` is deprecated, top-level facts will not be auto injected after the change. This feature will be removed from ansible-core version 2.24.
Origin: geerlingguy.apache/tasks/main.yml:4:17

2 # Include variables and define needed variables.
3 - name: Include OS-specific variables.
4   include_vars: "{{ ansible_os_family }}.yml"
                  ^ column 17

Use `ansible_facts["fact_name"]` (no `ansible_` prefix) instead.