Adopt @PHPUnit55Migration:risky rule of php-cs-fixer

Author: nicolas-grekas

Tests/Store/ExpiringStoreTestTrait.php

@@ -11,7 +11,6 @@
 
 namespace Symfony\Component\Lock\Tests\Store;
 
-use Symfony\Bridge\PhpUnit\ForwardCompatTestTrait;
 use Symfony\Component\Lock\Exception\LockExpiredException;
 use Symfony\Component\Lock\Key;
 use Symfony\Component\Lock\StoreInterface;