Update test stack: migrate to Foundry 2 and PHPUnit 11 (Case 212955)

[janopae]

Foundry 1 cannot run on Symfony 8, so it must be replaced before the final bump; on the interim Symfony 7 this can happen in isolation. Foundry 2 removed the ModelFactory base class — rewrite the four test factories onto PersistentProxyObjectFactory: getDefaults() → defaults(), getClass() → class() (public static), initialize() return type self → static. Because Foundry 2 requires PHPUnit >= 9.5 (and Foundry 1 does not run on PHPUnit 11), the PHPUnit 8.5 → 11 bump and the phpunit.xml schema update ride along in the same package.

Two additional fixes needed to make the suite green on PHPUnit 11:

• buildForm() and configureOptions(): add missing : void return type to the five form types that declared them without one (EmailAddressType, HoneypotType, StartRegistration\Type, EditRegistration\Type, DeleteRegistration\Type). mapDataToForms() and mapFormsToData() were already typed correctly; Command::execute(), the FlashBag→RequestStack replacement, and the routing 'attribute' switch were already in place from Package E.
• DetermineAppsSubclassHelper: skip eval()'d PHPUnit test-double classes when scanning get_declared_classes() for a RecipientInterface subclass. PHPUnit 11 auto-generates named stub classes (via eval()) for interface return types — these were picked up before App\Recipient, causing RecipientFactoryTest to fail in the full suite. PHP reports a synthetic filename for eval()'d code rather than false, so the guard uses is_file() to confirm a real file exists on disk.