MQE-2729: [PHP 8] Investigate and fix code related to changes in implode()

- update MFTF phpunit.xml file to follow latest schema

Author: okolesnyk

dev/tests/phpunit.xml

@@ -1,16 +1,25 @@
+<?xml version="1.0"?>
 <!--
  /**
   * Copyright © Magento, Inc. All rights reserved.
   * See COPYING.txt for license details.
   */
 -->
-
-<phpunit
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.1/phpunit.xsd"
-    convertNoticesToExceptions="false"
-    bootstrap="_bootstrap.php"
-    backupGlobals="false">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd" convertNoticesToExceptions="false"
+         bootstrap="_bootstrap.php" backupGlobals="false">
+    <coverage processUncoveredFiles="false">
+        <include>
+            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/DataGenerator</directory>
+            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Page</directory>
+            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Suite</directory>
+            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Test</directory>
+            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Util</directory>
+        </include>
+        <report>
+            <clover outputFile="build/logs/clover.xml"/>
+        </report>
+    </coverage>
     <testsuites>
         <testsuite name="verification">
             <directory>verification</directory>
@@ -19,16 +28,5 @@
             <directory>unit</directory>
         </testsuite>
     </testsuites>
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="false">
-            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/DataGenerator</directory>
-            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Page</directory>
-            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Suite</directory>
-            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Test</directory>
-            <directory suffix=".php">../../src/Magento/FunctionalTestingFramework/Util</directory>
-        </whitelist>
-    </filter>
-    <logging>
-        <log type="coverage-clover" target="build/logs/clover.xml"/>
-    </logging>
+    <logging/>
 </phpunit>