Use docker extensions for env variables

docker-compose.production.yml

@@ -5,21 +5,11 @@ volumes:
   static-files:
 
 services:
-  db:
-    env_file: ./.production.env
-
-  celery:
-    env_file: ./.production.env
-
-  django:
-    env_file: ./.production.env
-
   nginx:
     image: nginx:1.23
     depends_on:
       django:
         condition: service_healthy
-    env_file: ./.production.env
     ports:
       # Note that --env-file should be used to set these correctly
       - "${NGINX_HTTP_PORT:-80}:80"