Postgre compose.yml creates two volumes instead of one

[viadezo1er]

I also found a fix, see most recent PR.

Describe the bug

Postgre docker compose creates a useless volume (random name like 998e1a214a2ab50ce098dc9bda4952e65e48b524f055ee5192fcafd7052b3f09) that can be pruned after container has started.
Data does not persist after docker compose down.

To Reproduce
Steps to reproduce the behavior:
With this compose.yml:

services:
  postgres:
    image: postgres:18-alpine
    container_name: postgres-db
    restart: unless-stopped
    environment:
      POSTGRES_USER: myuser
      POSTGRES_PASSWORD: mypassword
      POSTGRES_DB: mydb
    ports:
      - "5432:5432"
    volumes:
      - postgres-data:/var/lib/postgresql/data

volumes:
  postgres-data:

docker compose up
docker volume ls
DRIVER    VOLUME NAME
local     998e1a214a2ab50ce098dc9bda4952e65e48b524f055ee5192fcafd7052b3f09
local     a_postgres-data

Expected behavior

Only one volume is created and data is persistent.

docker compose up
docker volume ls
DRIVER    VOLUME NAME
local     a_postgres-data