Update dependency phpunit/phpunit to v13

Author: renovate[bot]

composer.json

@@ -16,7 +16,7 @@
 		"automattic/jetpack-codesniffer": "7.0.0",
 		"dealerdirect/phpcodesniffer-composer-installer": "*",
 		"php-parallel-lint/php-parallel-lint": "1.4.0",
-		"phpunit/phpunit": "^12.0"
+		"phpunit/phpunit": "^13.0"
 	},
 	"scripts": {
 		"php:lint": [