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

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

composer.json

@@ -31,7 +31,7 @@
 	},
 	"require-dev": {
         "christophwurst/nextcloud_testing": "^1.0.1",
-		"phpunit/phpunit": "^9",
+		"phpunit/phpunit": "^12",
 		"nextcloud/coding-standard": "^1.4",
 		"bamarni/composer-bin-plugin": "^1.8.2"
 	},