[cs] remove unused use statements (#14661) [skip ci]

tests/framework/filters/AjaxFilterTest.php

@@ -10,7 +10,6 @@ namespace yiiunit\framework\filters;
 use Yii;
 use yii\base\Action;
 use yii\filters\AjaxFilter;
-use yii\web\BadRequestHttpException;
 use yii\web\Controller;
 use yii\web\Request;
 use yiiunit\TestCase;

tests/framework/i18n/FormatterTest.php

@@ -8,7 +8,6 @@
 namespace yiiunit\framework\i18n;
 
 use Yii;
-use yii\base\InvalidConfigException;
 use yii\i18n\Formatter;
 use yiiunit\TestCase;