Chore: Update docker-compose

docker-compose.yml

 version: "3.9"
 
 services:
-  db:
-    image: postgres
-    environment:
-      - POSTGRES_USER
-      - POSTGRES_PASSWORD
-      - POSTGRES_DB
-    volumes:
-      - postgres_data:/var/lib/postgresql/data
   web:
     image: ${CI_REGISTRY_IMAGE}:${CI_COMMIT_REF_NAME}
     environment:
       - ENV=production
       - SECRET_KEY
-      - DB_URL=postgresql://$POSTGRES_USER:$POSTGRES_PASSWORD@db/$POSTGRES_DB
-    depends_on:
-      - db
+      - DB_URL
   reverse_proxy:
     image: ${CI_REGISTRY_IMAGE}:${CI_COMMIT_REF_NAME}-nginx
     ports:
@@ -25,5 +15,3 @@ services:
     depends_on:
       - web
 
-volumes:
-  postgres_data: