chore(app): Fix test Group use statements

Author: lonnieezell

tests/system/Router/Attributes/CacheTest.php

@@ -19,6 +19,7 @@
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockAppConfig;
 use Config\Services;
+use PHPUnit\Framework\Attributes\Group;
 
 /**
  * @internal

tests/system/Router/Attributes/FilterTest.php

@@ -19,6 +19,7 @@
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockAppConfig;
 use Config\Services;
+use PHPUnit\Framework\Attributes\Group;
 
 /**
  * @internal

tests/system/Router/Attributes/RestrictTest.php

@@ -20,6 +20,7 @@
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockAppConfig;
 use Config\Services;
+use PHPUnit\Framework\Attributes\Group;
 
 /**
  * @internal