Migrate PHPUnit configuration file to 9.3

This silences a warning at test suite setup.

Author: NanoSector

phpunit.xml.dist

@@ -1,6 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-
-<phpunit colors="true" bootstrap="tests/bootstrap.php">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         colors="true"
+         bootstrap="tests/bootstrap.php"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+>
     <testsuites>
         <testsuite name="DoctrineBundle for the Symfony Framework">
             <directory>./tests</directory>
@@ -11,11 +14,11 @@
         <env name="SYMFONY_DEPRECATIONS_HELPER" value="ignoreFile=./tests/baseline-ignore"/>
     </php>
 
-    <filter>
-        <whitelist>
+    <coverage>
+        <include>
             <directory>src</directory>
-        </whitelist>
-    </filter>
+        </include>
+    </coverage>
 
     <listeners>
         <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener" />