breakout into separate playbooks for workflow testing

bigboot_rear_backup.yml

@@ -0,0 +1,15 @@
+---
+- name: Perform ReaR backup before the /boot expansion
+  hosts: all
+  become: true
+  gather_facts: true
+  strategy: free
+
+  tasks:
+    - name: Perform a ReaR backup if any disk modifications are to be made
+      ansible.builtin.import_playbook: rhc.rear.rear_backup
+      when:
+        - bigboot_execute_bigboot | bool
+        - not bigboot_skip_rear_backup | bool
+
+...