Fix false negatives in integration test for unused vars

Updated tests/integration/test_vars_usage_in_yaml.py:
- Variables immediately followed by '(' are now treated as function calls,
  not as set variables. This prevents false errors.
- Fixed detection of redirect_domain_mappings so it is no longer flagged
  as unused.

See: https://chatgpt.com/share/68c3542d-f44c-800f-a483-b3e43739f315

roles/web-app-akaunting/tasks/main.yml

@@ -11,10 +11,6 @@
 - name: "For '{{ application_id }}': load docker, db and proxy"
   include_role:
     name: sys-stk-full-stateful
-  vars:
-    # Forward flag into compose templating
-    cmp_extra_facts:
-      akaunting_setup_enabled: "{{ akaunting_setup_enabled }}"
 
 - name: "Akaunting | Create first-run marker to disable future setup"
   ansible.builtin.file: