Bump fastify from 5.8.3 to 5.8.5 in /functions

Bumps [fastify](https://github.com/fastify/fastify) from 5.8.3 to 5.8.5.
- [Release notes](https://github.com/fastify/fastify/releases)
- [Commits](fastify/fastify@v5.8.3...v5.8.5)

---
updated-dependencies:
- dependency-name: fastify
  dependency-version: 5.8.5
  dependency-type: direct:production
...

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

Author: dependabot[bot]

functions/package-lock.json

@@ -16,7 +16,7 @@
   "dependencies": {
     "@google-cloud/logging": "^11.0.0",
     "@valkey/valkey-glide": "^2.0.1",
-    "fastify": "^5.8.3",
+    "fastify": "^5.8.5",
     "firebase-admin": "^13.5.0",
     "firebase-functions": "^6.1.1"
   },