spreadsheet factory properties fix

modules/custom/arlista/src/Factory/SpreadSheetFactory.php

@@ -22,10 +22,10 @@ use PhpOffice\PhpSpreadsheet\Cell\DataType;
 
 class SpreadSheetFactory extends AbstractSpreadSheetFactory {
 
-  private $componentFactory;
-  private $manufacturerFactory;
-  private $categoryFactory;
-  private $manufacturer;
+  private ?ComponentFactory $componentFactory;
+  private ?ManufacturerFactory $manufacturerFactory;
+  private ?CategoryFactory $categoryFactory;
+  private ?Manufacturer $manufacturer;
   private ?Category $category = null;
   private ?Component $component = null;