minor #992 [Demo] Require PHPUnit 12 (OskarStark)

This PR was merged into the main branch.

Discussion
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[Demo] Require PHPUnit 12

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Docs?         | no
| Issues        | --
| License       | MIT

Commits
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3800cb4 Require PHPUnit 12 for demo application

Author: OskarStark

demo/composer.json

@@ -48,7 +48,7 @@
         "php-cs-fixer/shim": "^3.90",
         "phpstan/phpstan": "^2.1.32",
         "phpstan/phpstan-strict-rules": "^2.0.7",
-        "phpunit/phpunit": "^11.5.44",
+        "phpunit/phpunit": "^12.1",
         "symfony/browser-kit": "^7.3.6",
         "symfony/debug-bundle": "^7.3.5",
         "symfony/stopwatch": "^7.3",