chore(metadata): expand phpstan-return type annotations

[eliot488995568]

In src/State/SerializerContextBuilderInterface.php

Phpstan annotation return type need to define some special key or phpstan throw error because he cannot access to offset like 'groups'.

https://api-platform.com/docs/core/serialization/#changing-the-serialization-context-dynamically

//  File AbstractAdminContextBuilder.php who implements SerializerContextBuilderInterface
#[\Override]
public function createFromRequest(Request $request, bool $normalization, ?array $extractedAttributes = null): array
{
    $context = $this->decorated->createFromRequest($request, $normalization, $extractedAttributes);
    $resourceClass = $context['resource_class'] ?? null;
    $operation = $context['operation'] ?? null;
    $isItemOperation = $operation instanceof Get
        || $operation instanceof Patch
        || $operation instanceof Put;

    if ($resourceClass === $this->getApplicableResourceClass()) {
        if (!isset($context['groups'])) {
            $context['groups'] = [];
        }
        if (is_string($context['groups'])) {
            $context['groups'] = [$context['groups']];
        }
        if ($this->authorizationChecker->isGranted('ROLE_INVITED_USER')) {
            if ($normalization) {
                $context['groups'][] = 'timestamp:read';
                $context['groups'][] = 'blamable:read';
                $context['groups'][] = 'thing:read:user';
                $context['groups'][] = $this->getBaseSerializationGroup().':read:user';
                if ($isItemOperation) {
                    $context['groups'][] = 'thing:single:read:user';
                    $context['groups'][] = $this->getBaseSerializationGroup().':single:read:user';
                }
...