Fixed graphql unit test failing as it was extending from a wrong class (magento#134)

Co-authored-by: Sergio Vera <svera@adobe.com>

Author: m2-github-services

Magento2Framework/Tests/Header/CopyrightGraphQLUnitTest.php

@@ -5,9 +5,9 @@
  */
 namespace Magento2Framework\Tests\Header;
 
-use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+use Magento2\Tests\GraphQL\AbstractGraphQLSniffUnitTestCase;
 
-class CopyrightGraphQLUnitTest extends AbstractSniffUnitTest
+class CopyrightGraphQLUnitTest extends AbstractGraphQLSniffUnitTestCase
 {
     /**
      * @inheritdoc
@@ -22,12 +22,12 @@ public function getErrorList(): array
      */
     public function getWarningList($testFile = ''): array
     {
-        if ($testFile === 'CopyrightGraphQLUnitTest.1.graphqls' || 
+        if ($testFile === 'CopyrightGraphQLUnitTest.1.graphqls' ||
             $testFile === 'CopyrightGraphQLUnitTest.2.graphqls') {
             return [];
         }
 
-        if ($testFile === 'CopyrightGraphQLUnitTest.3.graphqls' || 
+        if ($testFile === 'CopyrightGraphQLUnitTest.3.graphqls' ||
             $testFile === 'CopyrightGraphQLUnitTest.4.graphqls') {
             return [
                 null => 1