chore: move prettier to root project

Author: openscript

apps/backend/package.json

@@ -61,7 +61,6 @@
     "@types/node": "^22.13.10",
     "@types/supertest": "^6.0.2",
     "jest": "^29.7.0",
-    "prettier": "^3.5.3",
     "source-map-support": "^0.5.21",
     "supertest": "^7.0.0",
     "ts-jest": "^29.2.6",

package.json

@@ -31,6 +31,7 @@
     "eslint-plugin-react-refresh": "^0.4.19",
     "globals": "^16.0.0",
     "nx": "^20.6.0",
+    "prettier": "^3.5.3",
     "typescript-eslint": "^8.26.1"
   },
   "engines": {