chore(deps): update postgres docker tag to v18

Author: renovate[bot]

docker-compose.yml

@@ -53,7 +53,7 @@ x-server: &base_server_setup
 
 services:
   db:
-    image: postgres:15-alpine
+    image: postgres:18-alpine
     environment:
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: postgres