Validate images based on image dimensions

Thanks for the patch! Functionality wise it was working properly for me (don't forget to update your EB Browser widget with the minimum resolution).

However, I did get the following PHP error/warning (most likely because of Drupal 10/PHP 8.1) on the EB Browser widget config form if you have not set the new config yet:

Deprecated function: explode(): Passing null to parameter #2 ($string) of type string is deprecated in Drupal\dropzonejs_eb_widget\Plugin\EntityBrowser\Widget\DropzoneJsEbWidget->buildConfigurationForm() (line 517 of modules/contrib/dropzonejs/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php).
Drupal\dropzonejs_eb_widget\Plugin\EntityBrowser\Widget\DropzoneJsEbWidget->buildConfigurationForm(Array, Object) (Line: 135)
Drupal\entity_browser\Form\WidgetsConfig->buildForm(Array, Object)

Therefore I added a small fix to the current patch.
From this:

$min_resolution = explode('x', $configuration['min_resolution']) + ['', ''];

To this:

if (isset($configuration['min_resolution'])) {
  $min_resolution = explode('x', $configuration['min_resolution']) + ['', ''];
}
else {
  $min_resolution = ['', ''];
}

In my opinion, this can be moved to RTBC, so also updating the status. Feel free to adjust if needed.

Fixed some weird character formatting of the WIDTH×HEIGHT description.

Could you provide interdiff for your changes? That would make it easier to review…

Sure, here is an interdiff:

There were validation changes in D11 and this is fairly complex, so it would definitely be useful to have test coverage for this. At lest it needs to be converted to a merge request to ensure that it still works.