PHPUnit configuration file is out-dated

[d70rr3s]

When executing, PHPUnit shows a warning since the file schema is for versions prior 9. The file needs to be updated with similar content:

<?xml version="1.0" encoding="UTF-8"?>
<!-- TODO set checkForUnintentionallyCoveredCode="true" once https://www.drupal.org/node/2626832 is resolved. -->
<!-- PHPUnit expects functional tests to be run with either a privileged user
 or your current system user. See core/tests/README.md and
 https://www.drupal.org/node/2116263 for details.
-->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         bootstrap="web/core/tests/bootstrap.php"
         colors="true"
         beStrictAboutOutputDuringTests="true"
         beStrictAboutChangesToGlobalState="true"
         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
  <!-- TODO set printerClass="\Drupal\Tests\Listeners\HtmlOutputPrinter" once
   https://youtrack.jetbrains.com/issue/WI-24808 is resolved. Drupal provides a
   result printer that links to the html output results for functional tests.
   Unfortunately, this breaks the output of PHPStorm's PHPUnit runner. However, if
   using the command line you can add
   - -printer="\Drupal\Tests\Listeners\HtmlOutputPrinter" to use it (note there
   should be no spaces between the hyphens).
  -->
  <php>
    <!-- Set error reporting to E_ALL. -->
    <ini name="error_reporting" value="32767"/>
    <!-- Do not limit the amount of memory tests take to run. -->
    <ini name="memory_limit" value="-1"/>
    <!-- Example SIMPLETEST_BASE_URL value: http://localhost -->
    <env name="SIMPLETEST_BASE_URL" value="http://apache"/>
    <!-- Example SIMPLETEST_DB value: mysql://username:password@localhost/databasename#table_prefix -->
    <env name="SIMPLETEST_DB" value="mysql://drupal:drupal@mariadb/drupal"/>
    <!-- Example BROWSERTEST_OUTPUT_DIRECTORY value: /path/to/webroot/sites/simpletest/browser_output -->
    <env name="BROWSERTEST_OUTPUT_DIRECTORY" value="/var/www/html/web/sites/simpletest/browser_output"/>
    <!-- To disable deprecation testing completely set SYMFONY_DEPRECATIONS_HELPER value: 'disabled' -->
    <env name="SYMFONY_DEPRECATIONS_HELPER" value="strict" />
    <!-- Example for changing the driver class for mink tests MINK_DRIVER_CLASS value: 'Drupal\FunctionalJavascriptTests\DrupalSelenium2Driver' -->
    <!-- Example for changing the driver args to mink tests MINK_DRIVER_ARGS value: '["http://127.0.0.1:8510"]' -->
    <!-- Example for changing the driver args to phantomjs tests MINK_DRIVER_ARGS_PHANTOMJS value: '["http://127.0.0.1:8510"]' -->
    <!-- Example for changing the driver args to webdriver tests MINK_DRIVER_ARGS_WEBDRIVER value: '["firefox", null, "http://localhost:4444/wd/hub"]' -->
    <env name="MINK_DRIVER_ARGS_WEBDRIVER" value='["chrome", {"browserName":"chrome","chromeOptions":{"args":["--disable-gpu","--headless", "--no-sandbox", "--disable-dev-shm-usage"]}}, "http://chrome:9515"]'/>
  </php>
  <testsuites>
    <testsuite name="unit">
      <file>./tests/TestSuites/UnitTestSuite.php</file>
    </testsuite>
    <testsuite name="kernel">
      <file>./tests/TestSuites/KernelTestSuite.php</file>
    </testsuite>
    <testsuite name="functional">
      <file>./tests/TestSuites/FunctionalTestSuite.php</file>
    </testsuite>
    <testsuite name="functional-javascript">
      <file>./tests/TestSuites/FunctionalJavascriptTestSuite.php</file>
    </testsuite>
  </testsuites>
  <listeners>
    <listener class="\Drupal\Tests\Listeners\DrupalListener">
    </listener>
    <!-- The Symfony deprecation listener has to come after the Drupal listener -->
    <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
    </listener>
  </listeners>
  <!-- Filter for coverage reports. -->
  <coverage cacheDirectory=".phpunit">
    <include>
      <directory>./web/modules/custom</directory>
      <directory>./web/themes/custom</directory>
    </include>
    <exclude>
      <directory suffix="TestBase.php">./</directory>
    </exclude>
  </coverage>
</phpunit>

IMPORTANT!: Do not update directly, since environment var substitution is being carry out during setup task. Check changes and apply vars properly.