Update dependency phpunit/phpunit to ^12.3.15

Author: renovate-runner[bot]

composer.json

@@ -23,7 +23,7 @@
  "php-parallel-lint/php-console-highlighter": "^1.0",
  "php-parallel-lint/php-parallel-lint": "^1.4.0",
  "phpstan/phpstan": "^2.1.29",
- "phpunit/phpunit": "^12.3.10",
+ "phpunit/phpunit": "^12.3.15",
  "rector/rector": "^2.1.7",
  "roave/backward-compatibility-check": "^8.14.0",
  "squizlabs/php_codesniffer": "^3.13.4",