Bump firebase-admin from 13.8.0 to 13.9.0

Bumps [firebase-admin](https://github.com/firebase/firebase-admin-node) from 13.8.0 to 13.9.0.
- [Release notes](https://github.com/firebase/firebase-admin-node/releases)
- [Changelog](https://github.com/firebase/firebase-admin-node/blob/main/CHANGELOG.md)
- [Commits](https://github.com/firebase/firebase-admin-node/compare/v13.8.0...v13.9.0)

---
updated-dependencies:
- dependency-name: firebase-admin
  dependency-version: 13.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -21,7 +21,7 @@
     "@discordjs/opus": "^0.10.0",
     "dotenv": "^17.4.2",
     "firebase": "^12.12.1",
-    "firebase-admin": "^13.8.0",
+    "firebase-admin": "^13.9.0",
     "he": "^1.2.0",
     "ms": "^2.1.3",
     "request": "^2.88.2",