fix(bootstrap): deploy all non-EOL core distros (keyrings, repos, versions)

roles/bootstrap/templates/debian.sources.list.j2

@@ -1,7 +1,7 @@
 # Managed by Ansible.
 {% set release = bootstrap_debian_release %}
-{% set mirror = system_cfg.mirror %}
-{% set components = 'main contrib non-free' ~ (' non-free-firmware' if (os_version | string) not in ['10', '11'] else '') %}
+{% set mirror = system_cfg.mirror | default('http://deb.debian.org/debian', true) %}
+{% set components = 'main contrib non-free non-free-firmware' %}
 
 deb {{ mirror }} {{ release }} {{ components }}
 deb-src {{ mirror }} {{ release }} {{ components }}