Fix integration tests (most likely caused by incorrect merge conflict…

… resolving):

error msg:
1) Magento\Catalog\Block\Adminhtml\Category\Checkboxes\TreeTest::testGetTreeJson
Error: Call to a member function getConnectionName() on null

/var/www/html/lib/internal/Magento/Framework/App/ResourceConnection.php:110
/var/www/html/app/code/Magento/Catalog/Model/ResourceModel/Category/Collection.php:570
...

ref: https://github.com/vpodorozh/mageos-magento2/actions/runs/7472531139/job/20334972566#step:6:39

app/code/Magento/Catalog/Model/ResourceModel/Category/Collection.php

@@ -567,8 +567,7 @@ private function getProductsCountFromCategoryTable(Category $item, string $websi
      */
     private function getProductsCountQuery(array $categoryIds, $addVisibilityFilter = true): Select
     {
-        $connections = $this->_resource->getConnection();
-        $categoryTable = $connections->getTableName('catalog_category_product_index');
+        $categoryTable = $this->_resource->getTableName('catalog_category_product_index');
         $select = $this->_conn->select()
             ->from(
                 ['cat_index' => $categoryTable],