fix: remove namespaces from Pest functional tests

Pest functional tests should not have namespace declarations
as they use the global namespace by design

Author: iamgerwin

tests/ArchTest.php

@@ -2,8 +2,6 @@
 
 declare(strict_types=1);
 
-namespace Iamgerwin\GsmModem\Tests;
-
 arch('it will not use debugging functions')
     ->expect(['dd', 'dump', 'ray'])
     ->each->not->toBeUsed();

tests/ExampleTest.php

@@ -2,8 +2,6 @@
 
 declare(strict_types=1);
 
-namespace Iamgerwin\GsmModem\Tests;
-
 it('can test', function () {
     expect(true)->toBeTrue();
 });