magento-engcom/import-export-improvements#49: Add strict type to new test case

Author: dmanners

app/code/Magento/CatalogImportExport/Test/Unit/Model/Import/Product/Validator/WeightTest.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\CatalogImportExport\Test\Unit\Model\Import\Product\Validator;
 
 use Magento\CatalogImportExport\Model\Import\Product;