chore(deps): update dependency phpunit/phpunit to v12

Author: renovate[bot]

composer.json

@@ -31,7 +31,7 @@
     "firebase/php-jwt": "^6.10"
   },
   "require-dev": {
-    "phpunit/phpunit": "^11.0"
+    "phpunit/phpunit": "^12.0"
   },
   "autoload": {
     "psr-4": {