Update PHPUnit configuration

Author: sebastianbergmann

phpunit.xml

@@ -1,13 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
          bootstrap="vendor/autoload.php"
          cacheResultFile=".phpunit.cache/test-results"
          executionOrder="depends,defects"
          forceCoversAnnotation="true"
          beStrictAboutCoversAnnotation="true"
          beStrictAboutOutputDuringTests="true"
          beStrictAboutTodoAnnotatedTests="true"
+         convertDeprecationsToExceptions="true"
          failOnRisky="true"
          failOnWarning="true"
          colors="true"