chore: streamline @types/node version

Author: openscript

apps/backend/package.json

@@ -52,7 +52,7 @@
     "@nestjs/schematics": "^10.2.3",
     "@nestjs/testing": "^10.4.15",
     "@types/jest": "^29.5.14",
-    "@types/node": "^22.10.1",
+    "@types/node": "^20.16.5",
     "@types/supertest": "^6.0.2",
     "jest": "^29.7.0",
     "prettier": "^3.4.2",