build: fix directories in docker compose

docker-compose.dev.yml

@@ -8,7 +8,7 @@ services:
     ports:
       - "5432:5432"
     volumes:
-      - ./server/db/postgres_vol:/var/lib/postgresql/data
+      - ${POSTGRES_DIR}:/var/lib/postgresql/data
       - ./server/db/schema.sql:/docker-entrypoint-initdb.d/schema.sql
 
   redis: