6.56.0

Included commits: 6.55.0...6.56.0

Improvements

• Improved SKU increment generation for abstract products with many product concretes by switching to paginated batch reads instead of loading all product concrete transfers at once, improving performance for large product catalogs.
• Introduced ProductRepositoryInterface::getProductConcreteSkusByAbstractProductId() to retrieve concrete product SKUs in configurable batches.
• Optimized AttributeEncoder by replacing the ProductToUtilEncodingService dependency with native PHP json_encode()/json_decode() calls.