Remove redundant backend production env template

.env.production.example

@@ -1,35 +0,0 @@
-# memberapi.ose.tw backend env (production)
-APP_ENV=production
-PORT=8000
-
-DB_HOST=postgresql
-DB_PORT=5432
-DB_NAME=member_center
-DB_USER=member_ose
-DB_PASSWORD=CHANGE_ME
-
-# Keycloak (preferred when KEYCLOAK_BASE_URL + KEYCLOAK_REALM are set)
-KEYCLOAK_BASE_URL=
-KEYCLOAK_REALM=
-KEYCLOAK_VERIFY_TLS=true
-KEYCLOAK_ISSUER=
-KEYCLOAK_JWKS_URL=
-KEYCLOAK_AUDIENCE=
-KEYCLOAK_CLIENT_ID=
-KEYCLOAK_CLIENT_SECRET=
-KEYCLOAK_TOKEN_ENDPOINT=
-KEYCLOAK_USERINFO_ENDPOINT=
-KEYCLOAK_ADMIN_CLIENT_ID=
-KEYCLOAK_ADMIN_CLIENT_SECRET=
-KEYCLOAK_ADMIN_REALM=
-
-PUBLIC_FRONTEND_ORIGINS=https://member.ose.tw,https://mkt.ose.tw,https://admin.ose.tw
-INTERNAL_SHARED_SECRET=CHANGE_ME
-MEMBER_REQUIRED_REALM_ROLES=admin,manager
-ADMIN_REQUIRED_REALM_ROLES=admin,manager
-
-# Cache backend: memory | redis
-CACHE_BACKEND=redis
-CACHE_REDIS_URL=redis://redis:6379/0
-CACHE_PREFIX=memberapi
-CACHE_DEFAULT_TTL_SECONDS=30