ipabackup role: Use FQCN for ansible.builtin

Use Fully Qualified Collection Name (FQCN) for ansible builtins. This is
ansible.builtin.set_fact instead of set_fact for example and aplies for
all actions that are part of ansible.builtin.

All the replaced ansible.builtins:
  assert, command, copy, debug, fail, fetch, file, import_playbook,
  import_tasks, include_role, include_tasks, include_vars, package,
  set_fact, shell, slurp, stat, systemd

roles/ipabackup/tasks/get_ipabackup_dir.yml

@@ -4,5 +4,5 @@
   register: result_ipabackup_get_backup_dir
 
 - name: Set IPA backup dir
-  set_fact:
+  ansible.builtin.set_fact:
     ipabackup_dir: "{{ result_ipabackup_get_backup_dir.backup_dir }}"