Update dependency phpunit/phpunit to v12

| datasource | package         | from    | to     |
| ---------- | --------------- | ------- | ------ |
| packagist  | phpunit/phpunit | 11.5.45 | 12.4.5 |


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

Author: renovate[bot]

composer.json

@@ -31,7 +31,7 @@
         "orchestra/testbench": "^10.6",
         "patchlevel/coding-standard": "^1.3.0",
         "phpstan/phpstan": "^2.1.32",
-        "phpunit/phpunit": "^11.5.45",
+        "phpunit/phpunit": "^12.0.0",
         "roave/security-advisories": "dev-master",
         "wnx/commonmark-markdown-renderer": "^1.4"
     },