Fix docblock

Author: VincentBean

src/Actions/RetryBulkRequest.php

@@ -26,7 +26,7 @@ public function retry(BulkRequest $bulkRequest, bool $onlyFailed): ?BulkRequest
 
         foreach ($bulkRequest->request as $index => $request) {
 
-            /** @var BulkOperation $operation */
+            /** @var ?BulkOperation $operation */
             $operation = $operations->where('operation_id', '=', $index)->first();
 
             if ($operation === null || ($onlyFailed && ! in_array($operation->status, OperationStatus::failedStatuses()))) {