add return statement to render method, remove changes from EavSetup.php

Author: Nazar65

app/code/Magento/Eav/Setup/EavSetup.php

@@ -797,7 +797,7 @@ private function _getValue($array, $key, $default = null)
         if (isset($array[$key]) && is_bool($array[$key])) {
             $array[$key] = (int)$array[$key];
         }
-        return $array[$key] ?? $default;
+        return isset($array[$key]) ? $array[$key] : $default;
     }
 
     /**
@@ -1102,7 +1102,7 @@ public function getAttribute($entityTypeId, $id, $field = null)
 
         $row = $setupCache->get($mainTable, $entityTypeId, $id);
         if ($field !== null) {
-            return $row[$field] ?? false;
+            return isset($row[$field]) ? $row[$field] : false;
         }
 
         return $row;

app/code/Magento/Ui/Component/AbstractComponent.php

@@ -5,14 +5,12 @@
  */
 namespace Magento\Ui\Component;
 
+use Magento\Framework\Data\ValueSourceInterface;
 use Magento\Framework\DataObject;
-use Magento\Framework\Exception\LocalizedException;
-use Magento\Framework\View\Element\UiComponentFactory;
-use Magento\Framework\View\Element\UiComponentInterface;
 use Magento\Framework\View\Element\UiComponent\ContextInterface;
 use Magento\Framework\View\Element\UiComponent\DataSourceInterface;
 use Magento\Framework\View\Element\UiComponent\ObserverInterface;
-use Magento\Framework\Data\ValueSourceInterface;
+use Magento\Framework\View\Element\UiComponentInterface;
 
 //phpcs:disable Magento2.Classes.AbstractApi
 /**
@@ -142,10 +140,12 @@ protected function prepareChildComponent(UiComponentInterface $component)
 
     /**
      * Produce and return block's html output
+     *
+     * @return string
      */
     public function toHtml()
     {
-        $this->render();
+        return $this->render();
     }
 
     /**