[Symfony 6] Add return types to Symfony\Component\HttpKernel\Controller\ArgumentValueResolverInterface implementations

Problem/Motivation

Symfony has added return types to Symfony\Component\HttpKernel\Controller\ArgumentValueResolverInterface:

    public function supports(Request $request, ArgumentMetadata $argument): bool;

    public function resolve(Request $request, ArgumentMetadata $argument): iterable;

We need to do the same for compatibility with Symfony 6.

Steps to reproduce

Proposed resolution

Add the return types.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet