Populate IncludeDescendants on ContentPublishedNotification when publishing branch (forward port of #20578).

Author: AndyButland

src/Umbraco.Core/Notifications/ContentPublishedNotification.cs

@@ -24,6 +24,7 @@ public ContentPublishedNotification(IEnumerable<IContent> target, EventMessages
 
     public ContentPublishedNotification(IEnumerable<IContent> target, EventMessages messages, bool includeDescendants)
         : base(target, messages) => IncludeDescendants = includeDescendants;
+
     /// <summary>
     /// Gets a enumeration of <see cref="IContent"/> which are being published.
     /// </summary>

src/Umbraco.Core/Services/ContentService.cs

@@ -2207,7 +2207,7 @@ internal IEnumerable<PublishResult> PublishBranch(
                     variesByCulture ? culturesPublished.IsCollectionEmpty() ? null : culturesPublished : ["*"],
                     null,
                     eventMessages));
-            scope.Notifications.Publish(new ContentPublishedNotification(publishedDocuments, eventMessages).WithState(notificationState));
+            scope.Notifications.Publish(new ContentPublishedNotification(publishedDocuments, eventMessages, true).WithState(notificationState));
 
             scope.Complete();
         }