chore(deps): update dependency phpstan/phpstan-phpunit to v1.3.15

Author: renovate[bot]

composer.json

@@ -24,7 +24,7 @@
     "phpbench/phpbench": "^1.2",
     "phpstan/extension-installer": "^1.1",
     "phpstan/phpstan": "1.10.38",
-    "phpstan/phpstan-phpunit": "1.3.14",
+    "phpstan/phpstan-phpunit": "1.3.15",
     "phpstan/phpstan-strict-rules": "1.5.1",
     "phpunit/phpunit": "^9.5 || ^10",
     "psr/http-message": "^1 || ^2",