Update dependency phpunit/phpunit to v12

Author: renovate[bot]

composer.json

@@ -40,7 +40,7 @@
         "psr/http-message": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "7.5.20|9.5.0",
+        "phpunit/phpunit": "12.0.2",
         "sunrise/coding-standard": "1.0.0",
         "sunrise/http-factory": "2.0.2"
     },