service: use include_vars instead of set_fact for database name

roles/service/tasks/database.yaml

@@ -1,7 +1,7 @@
 ---
-- name: Set database name
+- name: Include database variables
-  ansible.builtin.set_fact:
+  ansible.builtin.include_vars:
-    _service_database_name: "{{ service_name }}-{{ service_database_type }}"
+    file: database.yaml
 
 - name: Database container for {{ service_name }}
   ansible.builtin.include_role:

roles/service/vars/database.yaml

@@ -0,0 +1,2 @@
+---
+_service_database_name: "{{ service_name }}-{{ service_database_type }}"