Replace file_validate_extensions deprecated method to work with Drupal 11
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #3512483. -->
Reported by: [ankitv18](https://www.drupal.org/user/3550392)
Related to !39
>>>
<h3 id="summary-problem-motivation">Problem/Motivation</h3>
<p>Deprecated method:<br>
- file_validate_extensions : <a href="https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L157">https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L157</a> and <a href="https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L120">https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L120</a><br>
- file_validate_is_image: <a href="https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L156">https://git.drupalcode.org/project/gin_login/-/blob/2.1.x/src/Form/GinLoginConfigurationForm.php?ref_type=heads#L156</a></p>
<h3 id="summary-proposed-resolution">Proposed resolution</h3>
<p><a href="https://www.drupal.org/node/3363700">https://www.drupal.org/node/3363700</a></p>
issue