Issue #3244533 by andypost, daffie: usleep() usage triggers deprecations on PHP 8.1

core/tests/Drupal/KernelTests/Core/File/DirectoryTest.php

@@ -224,7 +224,7 @@ public function testMultiplePrepareDirectory() {
       elseif ($pid == 0) {
         // Sleep so that all the forks start preparing the directory at the same
         // time.
-        usleep(($time_to_start - microtime(TRUE)) * 1000000);
+        usleep((int) (($time_to_start - microtime(TRUE)) * 1000000));
         $file_system->prepareDirectory($directory, FileSystemInterface::CREATE_DIRECTORY);
         exit();
       }

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

@@ -65,7 +65,7 @@ public function testConcurrent() {
         $factory = new KeyValueDatabaseFactory($this->container->get('serialization.phpserialize'), Database::getConnection());
         $store = $factory->get('test');
         // Sleep so that all the forks start at the same time.
-        usleep(($time_to_start - microtime(TRUE)) * 1000000);
+        usleep((int) (($time_to_start - microtime(TRUE)) * 1000000));
         if ($function === 'getAll') {
           $this->assertIsArray($store->getAll());
         }