[TEST] Add PHPStan deprecation rules

Author: oliverklee

composer.json

@@ -42,6 +42,7 @@
 		"helmich/typo3-typoscript-lint": "2.5.2 || 3.3.0",
 		"phpstan/extension-installer": "1.4.3",
 		"phpstan/phpstan": "1.12.32",
+		"phpstan/phpstan-deprecation-rules": "1.2.1",
 		"phpstan/phpstan-phpunit": "1.4.2",
 		"phpstan/phpstan-strict-rules": "1.6.2",
 		"phpunit/phpunit": "9.6.34",