Add Symfony ^8.0 support alongside ^7.0 (PHP >= 8.2)

[Azmandios]

Summary

Originally this branch adapted the bundle to roach-php/core 3.2 + Symfony ^7.0 (registering HttpErrorMiddleware / ProxyMiddleware). It now also adds forward support for Symfony 8.x without any code changes:

• symfony/*: ^7.0 → ^7.0|^8.0 (require + require-dev).
• No bundle source changes are required (see Compatibility).
• Fix ItemNormalizer::getSupportedTypes(): it returned a list ([ItemInterface::class]) instead of a keyed map ([ItemInterface::class => true]), so the Symfony serializer never associated the normalizer with ItemInterface and roach:run --output failed with NotNormalizableValueException.
• Migrate the bundle test suite to PHPUnit 11 (static data provider; #[Small] / #[Medium] / #[DataProvider] attributes; SymfonyExtension instead of the removed SymfonyTestsListener).
• CI: matrix php 8.2–8.5 × SYMFONY_REQUIRE 7.4.*/8.0.*/8.1.* × prefer-lowest/prefer-stable; drop the obsolete psalm step.

Compatibility

No code changes are needed for Symfony 8: all Symfony classes imported by roach-php/core + this bundle exist in Symfony 8.1, and static analysis reports no undefined/not found errors. The bundle stays a thin wrapper (boot() → Roach::useContainer()).

Testing

• Bundle suite: 12 tests / 38 assertions green on Symfony 7.4 and on Symfony 8.1.
• CI matrix exercises both dependency bounds (prefer-lowest / prefer-stable).

Notes for maintainers

The bundle alone cannot be installed on Symfony 8.x yet: roach-php/core 3.2.1 requires symfony/* ^7.0 (console, css-selector, dom-crawler, event-dispatcher, options-resolver) and php ~8.2.0||~8.3.0||~8.4.0. Since this is a transitive constraint it cannot be patched after install — a matching constraint widening in roach-php/core is required first. For that reason the 8.0.* / 8.1.* CI cells are marked as allowed failures until core is updated upstream.