[export] order center alphabetically when generating an export

src/Bundle/ChillMainBundle/Form/Type/Export/PickCenterType.php

@@ -57,6 +57,9 @@ final class PickCenterType extends AbstractType
             $export->requiredRole()
         );
 
+        // order alphabetically
+        usort($centers, fn (Center $a, Center $b) => $a->getCenter() <=> $b->getName());
+
         $builder->add('center', EntityType::class, [
             'class' => Center::class,
             'choices' => $centers,