selfservice: 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

tests/selfservice/test_selfservice_client_context.yml

@@ -6,7 +6,7 @@
 
   tasks:
   - name: Include FreeIPA facts.
-    include_tasks: ../env_freeipa_facts.yml
+    ansible.builtin.include_tasks: ../env_freeipa_facts.yml
 
   # Test will only be executed if host is not a server.
   - name: Execute with server context in the client.
@@ -27,13 +27,13 @@
 # in upstream CI.
 
 - name: Test selfservice using client context, in client host.
-  import_playbook: test_selfservice.yml
+  ansible.builtin.import_playbook: test_selfservice.yml
   when: groups['ipaclients']
   vars:
     ipa_test_host: ipaclients
 
 - name: Test selfservice using client context, in server host.
-  import_playbook: test_selfservice.yml
+  ansible.builtin.import_playbook: test_selfservice.yml
   when: groups['ipaclients'] is not defined or not groups['ipaclients']
   vars:
     ipa_context: client