minor #12356 Update dama/doctrine-test-bundle docs (dmaicher)

This PR was squashed before being merged into the 4.3 branch (closes #12356).

Discussion
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Update dama/doctrine-test-bundle docs

PHPUnit test hooks can be used starting from PHPUnit version 7.1:
https://phpunit.readthedocs.io/en/7.1/extending-phpunit.html#extending-phpunit-testrunner

This will avoid deprecation notices.

See also dmaicher/doctrine-test-bundle@8f87ad0

ping @javiereguiluz

Commits
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bb6d4bf Update dama/doctrine-test-bundle docs

Author: javiereguiluz

testing/database.rst

@@ -48,12 +48,12 @@ Now, enable it as a PHPUnit extension or listener:
     <phpunit>
         <!-- ... -->
 
-        <!-- Add this in PHPUnit 8 or higher -->
+        <!-- Add this for PHPUnit 7.1 or higher -->
         <extensions>
             <extension class="DAMA\DoctrineTestBundle\PHPUnit\PHPUnitExtension"/>
         </extensions>
 
-        <!-- Add this in PHPUnit 7 or lower -->
+        <!-- Add this for PHPUnit 7.0 -->
         <listeners>
             <listener class="\DAMA\DoctrineTestBundle\PHPUnit\PHPUnitListener"/>
         </listeners>