composer: require stable packages outside of nette

Author: dg

composer.json

@@ -23,8 +23,8 @@
 "nette/di": "^3.1 || ^4.0",
 "latte/latte": "^2.11 || ^3.0.12",
 "tracy/tracy": "^2.9",
-"phpstan/phpstan": "^1.0",
-"psr/simple-cache": "^2.0 || ^3.0"
+"psr/simple-cache": "^2.0 || ^3.0",
+"phpstan/phpstan-nette": "^2.0@stable"
 },
 "conflict": {
 "latte/latte": ">=3.0.0 <3.0.12"