Install phpstan/phpstan-phpunit

Author: ondrejmirtes

composer.json

@@ -9,6 +9,7 @@
 		"php-parallel-lint/php-parallel-lint": "^1.2",
 		"phpstan/extension-installer": "^1.0",
 		"phpstan/phpstan": "^1.5",
+		"phpstan/phpstan-phpunit": "^1.1",
 		"phpstan/phpstan-strict-rules": "^1.0",
 		"phpunit/phpunit": "^9.5",
 		"symfony/process": "^5.2"