Bump ws from 8.20.1 to 8.21.0 in /demo_bot_server

Bumps [ws](https://github.com/websockets/ws) from 8.20.1 to 8.21.0.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](websockets/ws@8.20.1...8.21.0)

---
updated-dependencies:
- dependency-name: ws
  dependency-version: 8.21.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

demo_bot_server/package-lock.json

@@ -10,6 +10,6 @@
   "license": "ISC",
   "dependencies": {
     "openai": "^4.17.4",
-    "ws": "^8.20.1"
+    "ws": "^8.21.0"
   }
 }