Getting errors about incomplete schema

Problem/Motivation

When running PHPUnit tests for Webform GoogleSheets I'm getting following errors:

Drupal\Core\Config\Schema\SchemaIncompleteException: Schema errors for google_api_client.google_api_service_client.webform_googlesheets_test with the following errors: google_api_client.google_api_service_client.webform_googlesheets_test:auth_config missing schema, google_api_client.google_api_service_client.webform_googlesheets_test:access_token missing schema
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/Development/ConfigSchemaChecker.php:98
/builds/project/webform_googlesheets/vendor/symfony/event-dispatcher/EventDispatcher.php:246
/builds/project/webform_googlesheets/vendor/symfony/event-dispatcher/EventDispatcher.php:206
/builds/project/webform_googlesheets/vendor/symfony/event-dispatcher/EventDispatcher.php:56
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/Config.php:230
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php:260
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php:486
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php:239
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Entity/EntityBase.php:354
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php:617
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/ConfigInstaller.php:389
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Config/ConfigInstaller.php:149
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/ProxyClass/Config/ConfigInstaller.php:75
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Extension/ModuleInstaller.php:333
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/ProxyClass/Extension/ModuleInstaller.php:83
/builds/project/webform_googlesheets/web/core/lib/Drupal/Core/Test/FunctionalTestSetupTrait.php:500
/builds/project/webform_googlesheets/web/core/tests/Drupal/Tests/BrowserTestBase.php:555
/builds/project/webform_googlesheets/web/core/tests/Drupal/Tests/BrowserTestBase.php:367

https://git.drupalcode.org/project/webform_googlesheets/-/jobs/4677910

Proposed resolution

Fix the schema with supported types.