fix: remove stale Twins Lab demo link

public/portfolio-data.json

@@ -141,7 +141,6 @@
       "category": "iot",
       "level": "senior",
       "status": "Protótipo",
-      "demoUrl": "https://twins.evandro.dev.br",
       "githubUrl": "https://github.com/evandrodevbr/twins-lab",
       "badges": ["IoT", "SSE", "Código público"],
       "featured": true,