ENGCOM-3399: Static tests fixed.

Author: p-bystritsky

app/code/Magento/Catalog/Model/ResourceModel/Product/CategoryLink.php

@@ -118,7 +118,6 @@ private function processCategoryLinks($newCategoryPositions, &$oldCategoryPositi
         $result = ['changed' => [], 'updated' => []];
 
         $oldCategoryPositions = array_values($oldCategoryPositions);
-        $oldCategoryList = array_column($oldCategoryPositions, 'category_id');
         foreach ($newCategoryPositions as $newCategoryPosition) {
             $key = false;