Steps to reproduce the issue

Apply PR#40051

Expected result

No PHP warnings and Deprecated messages

Actual result

PHP Warning:  Undefined array key "link" in C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php on line 734

PHP Deprecated:  preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php on line 734

System information (as much as possible)

Patch Tester 4.2.1
Joomla 4.2.9-dev of 14 March
PHP 8.1.10
Wampserver 3.3.1
Windows 11

Additional comments

[14-Mar-2023 03:14:43 UTC] PHP Warning:  Trying to access array offset on value of type null in C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php on line 734
[14-Mar-2023 03:14:43 UTC] PHP Stack trace:
[14-Mar-2023 03:14:43 UTC] PHP   1. {main}() C:\www\joomla4test\administrator\index.php:0
[14-Mar-2023 03:14:43 UTC] PHP   2. require_once() C:\www\joomla4test\administrator\index.php:32
[14-Mar-2023 03:14:43 UTC] PHP   3. Joomla\CMS\Application\CMSApplication->execute() C:\www\joomla4test\administrator\includes\app.php:61
[14-Mar-2023 03:14:43 UTC] PHP   4. Joomla\CMS\Application\AdministratorApplication->doExecute() C:\www\joomla4test\libraries\src\Application\CMSApplication.php:294
[14-Mar-2023 03:14:43 UTC] PHP   5. Joomla\CMS\Application\AdministratorApplication->dispatch($component = *uninitialized*) C:\www\joomla4test\libraries\src\Application\AdministratorApplication.php:186
[14-Mar-2023 03:14:43 UTC] PHP   6. Joomla\CMS\Component\ComponentHelper::renderComponent($option = 'com_patchtester', $params = *uninitialized*) C:\www\joomla4test\libraries\src\Application\AdministratorApplication.php:143
[14-Mar-2023 03:14:43 UTC] PHP   7. Joomla\CMS\Dispatcher\LegacyComponentDispatcher->dispatch() C:\www\joomla4test\libraries\src\Component\ComponentHelper.php:355
[14-Mar-2023 03:14:43 UTC] PHP   8. Joomla\CMS\Dispatcher\LegacyComponentDispatcher::Joomla\CMS\Dispatcher\{closure:C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:70-72}($path = 'C:\\www\\joomla4test\\administrator/components/com_patchtester/patchtester.php') C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:73
[14-Mar-2023 03:14:43 UTC] PHP   9. require_once() C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:71
[14-Mar-2023 03:14:43 UTC] PHP  10. PatchTester\Controller\ApplyController->execute() C:\www\joomla4test\administrator\components\com_patchtester\patchtester.php:44
[14-Mar-2023 03:14:43 UTC] PHP  11. PatchTester\Model\PullModel->apply($id = 40051) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Controller\ApplyController.php:39
[14-Mar-2023 03:14:43 UTC] PHP  12. PatchTester\Model\PullModel->applyWithGitHub($id = 40051) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php:122
[14-Mar-2023 03:14:43 UTC] PHP  13. PatchTester\Model\PullModel->getFiles($id = 40051, $page = 1, $files = *uninitialized*) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php:538

[14-Mar-2023 03:14:43 UTC] PHP Deprecated:  preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php on line 734
[14-Mar-2023 03:14:43 UTC] PHP Stack trace:
[14-Mar-2023 03:14:43 UTC] PHP   1. {main}() C:\www\joomla4test\administrator\index.php:0
[14-Mar-2023 03:14:43 UTC] PHP   2. require_once() C:\www\joomla4test\administrator\index.php:32
[14-Mar-2023 03:14:43 UTC] PHP   3. Joomla\CMS\Application\CMSApplication->execute() C:\www\joomla4test\administrator\includes\app.php:61
[14-Mar-2023 03:14:43 UTC] PHP   4. Joomla\CMS\Application\AdministratorApplication->doExecute() C:\www\joomla4test\libraries\src\Application\CMSApplication.php:294
[14-Mar-2023 03:14:43 UTC] PHP   5. Joomla\CMS\Application\AdministratorApplication->dispatch($component = *uninitialized*) C:\www\joomla4test\libraries\src\Application\AdministratorApplication.php:186
[14-Mar-2023 03:14:43 UTC] PHP   6. Joomla\CMS\Component\ComponentHelper::renderComponent($option = 'com_patchtester', $params = *uninitialized*) C:\www\joomla4test\libraries\src\Application\AdministratorApplication.php:143
[14-Mar-2023 03:14:43 UTC] PHP   7. Joomla\CMS\Dispatcher\LegacyComponentDispatcher->dispatch() C:\www\joomla4test\libraries\src\Component\ComponentHelper.php:355
[14-Mar-2023 03:14:43 UTC] PHP   8. Joomla\CMS\Dispatcher\LegacyComponentDispatcher::Joomla\CMS\Dispatcher\{closure:C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:70-72}($path = 'C:\\www\\joomla4test\\administrator/components/com_patchtester/patchtester.php') C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:73
[14-Mar-2023 03:14:43 UTC] PHP   9. require_once() C:\www\joomla4test\libraries\src\Dispatcher\LegacyComponentDispatcher.php:71
[14-Mar-2023 03:14:43 UTC] PHP  10. PatchTester\Controller\ApplyController->execute() C:\www\joomla4test\administrator\components\com_patchtester\patchtester.php:44
[14-Mar-2023 03:14:43 UTC] PHP  11. PatchTester\Model\PullModel->apply($id = 40051) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Controller\ApplyController.php:39
[14-Mar-2023 03:14:43 UTC] PHP  12. PatchTester\Model\PullModel->applyWithGitHub($id = 40051) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php:122
[14-Mar-2023 03:14:43 UTC] PHP  13. PatchTester\Model\PullModel->getFiles($id = 40051, $page = 1, $files = *uninitialized*) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php:538

[14-Mar-2023 03:14:43 UTC] PHP  14. preg_match($pattern = '/(\\?page=[0-9]{1,3}>; rel=\\"last\\")/', $subject = NULL, $matches = NULL) C:\www\joomla4test\administrator\components\com_patchtester\PatchTester\Model\PullModel.php:734