ipaserver 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/ipaserver/tasks/copy_external_cert.yml

@@ -1,14 +1,14 @@
 ---
 - name: Install - Initialize ipaserver_external_cert_files
-  set_fact:
+  ansible.builtin.set_fact:
      ipaserver_external_cert_files: []
   when: ipaserver_external_cert_files is undefined
 - name: Install - Copy "{{ item }}" "{{ inventory_hostname }}':/root/'{{ item | basename }}"
-  copy:
+  ansible.builtin.copy:
     src: "{{ item }}"
     dest: "/root/{{ item | basename }}"
     mode: preserve
     force: yes
 - name: Install - Extend ipaserver_external_cert_files with "/root/{{ item | basename }}"
-  set_fact:
+  ansible.builtin.set_fact:
     ipaserver_external_cert_files: "{{ ipaserver_external_cert_files + [ '/root/' + (item | basename) ] }}"