Fix Magento bug #34464

[Genaker]

Change: In Magento\Framework\ObjectManager\Config\Config::_mergeConfiguration(), replace array_replace with array_replace_recursive so array arguments are merged instead of overwritten across areas

Description (*)

In Magento\Framework\ObjectManager\Config\Config::_mergeConfiguration(), array arguments are merged using array_replace(). When a type is configured in global etc/di.xml with array arguments (e.g. collections), and the same type is modified in area-specific etc/adminhtml/di.xml (e.g. adding a plugin or more arguments), the entire array value is replaced instead of merged. Global entries are lost, causing "Not registered handle" errors on admin grids (e.g. CMS Blocks, Pages).

Change: Replace array_replace with array_replace_recursive so nested array arguments are merged by key. This preserves both global and area-specific items.

File: ObjectManager/Config/Config.php (line ~261)

Fixed Issues (if relevant)

Bug in DI generation: array arguments got replaced instead of merging when modified from different area #34464

1. Fixes Bug in DI generation: array arguments got replaced instead of merging when modified from different area #34464

Manual testing scenarios (*)

1. Create a custom module with global etc/di.xml adding a collections item to Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory.
2. Add etc/adminhtml/di.xml in the same module with a plugin on CollectionFactory and an additional collections item.
3. In admin area, verify CollectionFactory::getReport('cms_block_listing_data_source') succeeds (no "Not registered handle" exception).
4. Open Content > Blocks and Content > Pages in admin; both grids should load without errors.
5. Open Sales > Orders; order grid should load without errors.

Questions or comments

array_replace_recursive preserves existing behavior when no nested keys overlap. When keys overlap, the second value wins (same as array_replace for that key), but sibling keys are now merged instead of lost.

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[Genaker]

@magento run all tests