fix: ai-assistants-samples/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-LANGCHAIN-8310293
- https://snyk.io/vuln/SNYK-JS-LANGCHAIN-8310492

ai-assistants-samples/package.json

@@ -9,7 +9,7 @@
     "@twilio/runtime-handler": "1.3.0",
     "exa-js": "^1.0.12",
     "jsonwebtoken": "^9.0.2",
-    "langchain": "^0.1.21",
+    "langchain": "^0.3.3",
     "twilio": "^3.56"
   }
 }