Issue #3400313 by kim.pepper, catch: Skip KeyValueStore\DatabaseStorageTest...

Issue #3400313 by kim.pepper, catch: Skip KeyValueStore\DatabaseStorageTest due to random test failures

core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageTest.php

@@ -36,6 +36,7 @@ public function register(ContainerBuilder $container) {
    * Tests asynchronous table creation.
    */
   public function testConcurrent() {
+    $this->markTestSkipped("Skipped due to frequent random test failures. See https://www.drupal.org/project/drupal/issues/3398063");
     if (!function_exists('pcntl_fork')) {
       $this->markTestSkipped('Requires the pcntl_fork() function');
     }