fix: correct formatting in package.json overrides section

Author: JasonKrik

services/backend/package.json

@@ -50,7 +50,7 @@
       "@esbuild-kit/core-utils": {
         "esbuild": "0.25.2"
       }
-    }
+    },
     "typescript-eslint": "^8.33.0"
   }
 }