hide compression in backup job update form

app/UI/BackupJob/Forms/UpdateForm.php

@@ -105,6 +105,7 @@ class UpdateForm extends BaseForm implements ClientArea
             "zstd" => sl("lang")->tr("zstd")
         ]);
         $field->setDefaultValue('zstd');
+        $field->addClass('hidden');
         $field->notEmpty();
         $this->addField($field);
         //mode