Fix ActivityPubDeliveryService

app/Services/ActivityPubDeliveryService.php

@@ -374,7 +374,8 @@ class ActivityPubDeliveryService
                                 'body' => $payload,
                             ]);
                     }
-                }
+                },
+                self::concurrency()
             );
 
             $deliveriesByIndex = [];
@@ -486,6 +487,14 @@ class ActivityPubDeliveryService
         return $result;
     }
 
+    private static function concurrency(): int
+    {
+        return max(
+            1,
+            (int) config('federation.activitypub.delivery.concurrency', 10)
+        );
+    }
+
     /**
      * Validate that the profile is a local, active profile that may be used
      * to sign outgoing ActivityPub requests.