service: 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/service/test_service_without_skip_host_check.yml

@@ -8,7 +8,7 @@
   # setup
 
   - name: Setup test environment
-    include_tasks: env_setup.yml
+    ansible.builtin.include_tasks: env_setup.yml
 
   # tests
   - name: Ensure service is present
@@ -461,4 +461,4 @@
 
   # cleanup
   - name: Cleanup test environment
-    include_tasks: env_cleanup.yml
+    ansible.builtin.include_tasks: env_cleanup.yml