[export] fix acp ReferrerScopeAggregator query + unit test

TO CHECK: logic in alterQuery. calc_date is same for 2 histories ?

src/Bundle/ChillCalendarBundle/Export/Aggregator/ScopeAggregator.php

@@ -74,6 +74,7 @@ final readonly class ScopeAggregator implements AggregatorInterface
     {
         $builder->add('scope_at', PickRollingDateType::class, [
             'label' => 'export.calendar.agent_scope.Calc date',
+            'required' => true,
         ]);
     }
     public function getFormDefaultData(): array