feat(dc): move postgres to external db

docker-compose.yml

@@ -1,20 +1,4 @@
 services:
-  db:
-    image: postgres:16.9@sha256:47053cd4ee3f096afc744e53e3280de7b29b3670d2f2196c2acc0c6470923c99
-    restart: unless-stopped
-    volumes:
-      - db-data:/var/lib/postgresql/data
-    environment:
-      - POSTGRES_PASSWORD=${DC_VIKUNJA_POSTGRES_PASSWORD:?}
-      - POSTGRES_DB=${DC_VIKUNJA_POSTGRES_DB:-db}
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U postgres"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    networks:
-      - vikunja
-
   vikunja:
     image: vikunja/vikunja:0.24.6@sha256:ed1f3ed467fecec0b57e9de7bc6607f8bbcbb23ffced6a81f5dfefc794cdbe3b
     environment:
@@ -41,20 +25,13 @@ services:
       - "traefik.enable=true"
       - "traefik.http.routers.vikunja.rule=Host(`${DC_VIKUNJA_HOSTNAME:?}`)"
       - "traefik.http.routers.vikunja.entrypoints=websecure"
-    depends_on:
-      db:
-        condition: service_healthy
     restart: unless-stopped
     networks:
-      - vikunja
       - traefik
 
 networks:
-  vikunja:
-    external: false
   traefik:
     external: true
 
 volumes:
-  db-data:
   files: