fix(deps): update dependency fastify to v5.6.2 (freeCodeCamp#65261)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

api/package.json

@@ -21,7 +21,7 @@
     "date-fns-tz": "3.2.0",
     "dotenv": "16.6.1",
     "fast-uri": "2.4.0",
-    "fastify": "5.2.0",
+    "fastify": "5.6.2",
     "fastify-plugin": "5.1.0",
     "joi": "17.13.3",
     "jsonwebtoken": "9.0.2",