deps(react-ai): remove unused dev deps (#6481)

Author: calebpollman

packages/react-ai/package.json

@@ -52,10 +52,6 @@
     "@aws-amplify/ui-react": "^6.9.0",
     "@aws-amplify/ui-react-core": "^3.3.0"
   },
-  "devDependencies": {
-    "@types/jest-when": "^3.5.0",
-    "jest-when": "^3.5.1"
-  },
   "size-limit": [
     {
       "name": "AIConversation",