chore: add jest deps

Author: ericapisani

demos/next-auth/package.json

@@ -29,6 +29,7 @@
     "react-dom": "^17.0.2"
   },
   "devDependencies": {
+    "@types/jest": "^27.4.1",
     "@types/node": "^17.0.14",
     "@types/react": "^17.0.39",
     "husky": "^7.0.4",