Add snooze for test stability.

module/VuFind/tests/integration-tests/src/VuFindTest/Mink/BulkTest.php

@@ -241,6 +241,7 @@ class BulkTest extends \VuFindTest\Unit\MinkTestCase
         // Do the export:
         $submit = $this->findCss($page, '.modal-body input[name=submit]');
         $submit->click();
+        $this->snooze();
         $result = $this->findCss($page, '.modal-body .alert .text-center .btn');
         $this->assertEquals('Download File', $result->getText());
     }