Reference phpunit.xsd from vendor

Author: ondrejmirtes

phpunit.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd" bootstrap="tests/bootstrap.php" cacheResult="false" colors="true" executionOrder="random" failOnRisky="true" failOnWarning="true" failOnEmptyTestSuite="true" beStrictAboutChangesToGlobalState="true" beStrictAboutOutputDuringTests="true" cacheDirectory=".phpunit.cache" beStrictAboutCoverageMetadata="true">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd" bootstrap="tests/bootstrap.php" cacheResult="false" colors="true" executionOrder="random" failOnRisky="true" failOnWarning="true" failOnEmptyTestSuite="true" beStrictAboutChangesToGlobalState="true" beStrictAboutOutputDuringTests="true" cacheDirectory=".phpunit.cache" beStrictAboutCoverageMetadata="true">
   <testsuites>
     <testsuite name="PHPStan">
       <directory suffix="Test.php">tests/PHPStan</directory>