service: Make postgres version configurable

roles/service/tasks/database.yml

@@ -2,7 +2,7 @@
 
 - name: Set postgres container vars
   ansible.builtin.set_fact:
-    db_container_image: 'postgres:14-alpine'
+    db_container_image: 'postgres:{{ docker_postgres_tag }}'
     db_container_env:
       POSTGRES_USER: "{{ docker_service_underscore_name }}"
       POSTGRES_PASSWORD: "{{ database_passwords[docker_service_name] }}"