Update kalnoy/nestedset to stable version

Author: Riari

composer.json

@@ -21,7 +21,7 @@
     "require": {
         "php": "^8.2",
         "laravel/framework": "^11.0",
-        "kalnoy/nestedset": "v6.x-dev",
+        "kalnoy/nestedset": "^6.0",
         "doctrine/dbal": "^4.0"
     },
     "require-dev": {