ElasticSearch ItemNormalizer has incorrect return type on normalize

[Koenstell]

API Platform version(s) affected: 3.3.11

Description
When using API Platform combined with Elasticsearch, it will prioritize the ItemNormalizer to allow documents from Elastic to be normalized as well. However, the method signature of this class does not comply with its parents, which means that if somewhere else you use a normalizer through the NormalizerInterface DI, you could end up with this error:

ApiPlatform\Elasticsearch\Serializer\ItemNormalizer::normalize(): Return value must be of type array, string returned

How to reproduce

• Use API Platform with Elasticsearch enabled
• Inject the normalizer in a random controller using DI: private readonly NormalizerInterface $normalizer
• Try to normalize an entity manually: $this->normalizer->normalize($entity, null, ['groups' => ['example']]);

Possible Solution
Change the method signature of the ElasticSearch ItemNormalizer. Located at ApiPlatform\Elasticsearch\Serializer\ItemNormalizer.

Like so:
BEFORE

public function normalize(mixed $object, ?string $format = null, array $context = []): array
{
    return $this->decorated->normalize($object, $format, $context);
}

AFTER:

public function normalize(mixed $object, ?string $format = null, array $context = []): \ArrayObject|array|string|int|float|bool|null
{
    return $this->decorated->normalize($object, $format, $context);
}