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/itop-tickets/itopTicketTest.php

@@ -39,14 +39,6 @@ class ItopTicketTest extends ItopDataTestCase
 {
 	const CREATE_TEST_ORG = true;
 
-	/**
-     * @throws Exception
-     */
-    protected function setUp()
-	{
-		parent::setUp();
-	}
-
 	/**
      * <pre>
 	 * Given: