fix: frontend and backend now get variables at build time not runtime

docker-compose.yaml

@@ -1,30 +1,32 @@
 services:
   frontend:
+    env_file: .env
     build:
       context: ./frontend
       dockerfile: Dockerfile
+      args:
+        NEXT_PUBLIC_BACKEND_URL: ${NEXT_PUBLIC_BACKEND_URL}
     container_name: werkzeugkiste-frontend
-    env_file: .env
     environment:
       - NODE_ENV=${NODE_ENV}
       - HOSTNAME=${HOSTNAME}
       - PORT=${FRONTEND_PORT}
-      - NEXT_PUBLIC_BACKEND_URL=${NEXT_PUBLIC_BACKEND_URL}
     ports:
       - "${FRONTEND_PORT}:3000"
     restart: unless-stopped
 
   backend:
+    env_file: .env
     build:
       context: ./backend
       dockerfile: Dockerfile
+      args:
+        CORS_ALLOWED_ORIGIN: ${CORS_ALLOWED_ORIGIN}
     container_name: werkzeugkiste-backend
-    env_file: .env
     environment:
       - NODE_ENV=${NODE_ENV}
       - HOSTNAME=${HOSTNAME}
       - PORT=${BACKEND_PORT}
-      - CORS_ALLOWED_ORIGIN=${CORS_ALLOWED_ORIGIN}
     ports:
       - "${BACKEND_PORT}:4000"
     restart: unless-stopped