N°3091 Update PHPUnit to 8.5 : fix setUp and teardDown methods signatures

"Return type declaration must be compatible with parent"
See https://phpunit.de/announcements/phpunit-8.html "Return Type of Template Methods"

test/application/composer/iTopComposerTest.php

@@ -27,7 +27,7 @@ use Combodo\iTop\Test\UnitTest\ItopTestCase;
 class iTopComposerTest extends ItopTestCase
 {
 
-	protected function setUp()
+	protected function setUp(): void
 	{
 		parent::setUp();
 		clearstatcache();