build(deps): bump fastify

Bumps the npm_and_yarn group with 1 update in the /services/user-service directory: [fastify](https://github.com/fastify/fastify).


Updates `fastify` from 5.8.1 to 5.8.4
- [Release notes](https://github.com/fastify/fastify/releases)
- [Commits](https://github.com/fastify/fastify/compare/v5.8.1...v5.8.4)

---
updated-dependencies:
- dependency-name: fastify
  dependency-version: 5.8.4
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

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

services/user-service/package-lock.json

@@ -16,7 +16,7 @@
         "@connectrpc/connect-fastify": "^2.1.1",
         "@connectrpc/protoc-gen-connect-es": "^0.13.2",
         "@types/mongoose-unique-validator": "^1.0.7",
-        "fastify": "^5.8.1",
+        "fastify": "^5.8.4",
         "kafkajs": "^2.2.4",
         "mongoose": "^7.8.6",
         "mongoose-unique-validator": "^4.0.0",
@@ -3616,9 +3616,9 @@
       }
     },
     "node_modules/fastify": {
-      "version": "5.8.1",
-      "resolved": "https://registry.npmjs.org/fastify/-/fastify-5.8.1.tgz",
-      "integrity": "sha512-y0kicFvvn7CYWoPOVLOcvn4YyKQz03DIY7UxmyOy21/J8eXm09R+tmb+tVDBW5h+pja30cHI5dqUcSlvY86V2A==",
+      "version": "5.8.4",
+      "resolved": "https://registry.npmjs.org/fastify/-/fastify-5.8.4.tgz",
+      "integrity": "sha512-sa42J1xylbBAYUWALSBoyXKPDUvM3OoNOibIefA+Oha57FryXKKCZarA1iDntOCWp3O35voZLuDg2mdODXtPzQ==",
       "funding": [
         {
           "type": "github",