A typical deprecation that you can find in your custom code is:
Function entity_delete_multiple not found.
Change your code from
$results = \Drupal::entityQuery('node')
->condition('type', 'article')
->execute();
if ($hasResults) {
entity_delete_multiple('node', $results);
}
to
if ($hasResults) {
$storage_handler = \Drupal::entityTypeManager()->getStorage('node');
$storage_handler->delete($results);
}