Bump @azure/identity in /app-auth/graphapponlytutorial

Bumps [@azure/identity](https://github.com/Azure/azure-sdk-for-js) from 4.8.0 to 4.9.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-js/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-js/blob/main/documentation/Changelog-for-next-generation.md)
- [Commits](https://github.com/Azure/azure-sdk-for-js/compare/@azure/identity_4.8.0...@azure/identity_4.9.0)

---
updated-dependencies:
- dependency-name: "@azure/identity"
  dependency-version: 4.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

app-auth/graphapponlytutorial/package-lock.json

@@ -19,7 +19,7 @@
     "prettier": "^3.5.3"
   },
   "dependencies": {
-    "@azure/identity": "^4.8.0",
+    "@azure/identity": "^4.9.0",
     "@microsoft/microsoft-graph-client": "^3.0.7",
     "isomorphic-fetch": "^3.0.0",
     "readline-sync": "^1.4.10"