chore(deps): bump @fastify/cookie from 9.2.0 to 9.3.0 in /backend

Bumps [@fastify/cookie](https://github.com/fastify/fastify-cookie) from 9.2.0 to 9.3.0.
- [Release notes](https://github.com/fastify/fastify-cookie/releases)
- [Commits](fastify/fastify-cookie@v9.2.0...v9.3.0)

---
updated-dependencies:
- dependency-name: "@fastify/cookie"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/package.json

@@ -10,7 +10,7 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "@fastify/cookie": "^9.2.0",
+    "@fastify/cookie": "^9.3.0",
     "@fastify/cors": "^8.5.0",
     "@supabase/auth-helpers-nextjs": "^0.8.7",
     "@supabase/ssr": "^0.0.10",