build(deps): bump fastify from 5.4.0 to 5.5.0 in /backend

Bumps [fastify](https://github.com/fastify/fastify) from 5.4.0 to 5.5.0.
- [Release notes](https://github.com/fastify/fastify/releases)
- [Commits](https://github.com/fastify/fastify/compare/v5.4.0...v5.5.0)

---
updated-dependencies:
- dependency-name: fastify
  dependency-version: 5.5.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/package-lock.json

@@ -12,7 +12,7 @@
         "@fastify/type-provider-typebox": "^5.2.0",
         "@types/jest": "^30.0.0",
         "@types/nodemailer": "^6.4.17",
-        "fastify": "^5.4.0",
+        "fastify": "^5.5.0",
         "nodemailer": "^7.0.5",
         "ts-dotenv": "^0.9.1"
       },
@@ -4836,9 +4836,9 @@
       "license": "BSD-3-Clause"
     },
     "node_modules/fastify": {
-      "version": "5.4.0",
-      "resolved": "https://registry.npmjs.org/fastify/-/fastify-5.4.0.tgz",
-      "integrity": "sha512-I4dVlUe+WNQAhKSyv15w+dwUh2EPiEl4X2lGYMmNSgF83WzTMAPKGdWEv5tPsCQOb+SOZwz8Vlta2vF+OeDgRw==",
+      "version": "5.5.0",
+      "resolved": "https://registry.npmjs.org/fastify/-/fastify-5.5.0.tgz",
+      "integrity": "sha512-ZWSWlzj3K/DcULCnCjEiC2zn2FBPdlZsSA/pnPa/dbUfLvxkD/Nqmb0XXMXLrWkeM4uQPUvjdJpwtXmTfriXqw==",
       "funding": [
         {
           "type": "github",

backend/package.json

@@ -46,7 +46,7 @@
     "@fastify/type-provider-typebox": "^5.2.0",
     "@types/jest": "^30.0.0",
     "@types/nodemailer": "^6.4.17",
-    "fastify": "^5.4.0",
+    "fastify": "^5.5.0",
     "nodemailer": "^7.0.5",
     "ts-dotenv": "^0.9.1"
   },