Revert "Update dead-code-detector"

This reverts commit 56eef73.

Author: ondrejmirtes

composer.json

@@ -66,7 +66,7 @@
 		"phpstan/phpstan-strict-rules": "^2.0",
 		"phpunit/phpunit": "^11.5.23",
 		"shipmonk/composer-dependency-analyser": "^1.5",
-		"shipmonk/dead-code-detector": "^0.13.5",
+		"shipmonk/dead-code-detector": "^0.12.0",
 		"shipmonk/name-collision-detector": "^2.0"
 	},
 	"config": {