Fix async lambda warnings in queue events documentation

Remove async keyword from event handler lambdas that have no await, replacing them with synchronous lambdas that return Task.CompletedTask. Also fix Enqueuing handler to use args.Data instead of args.Entry.Value.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: niemyjski

docs/guide/queues.md

@@ -391,34 +391,40 @@ Subscribe to queue lifecycle events:
 ```csharp
 var queue = new InMemoryQueue<WorkItem>();
 
-queue.Enqueuing.AddHandler(async (sender, args) =>
+queue.Enqueuing.AddHandler((sender, args) =>
 {
-    _logger.LogInformation("Enqueuing: {Data}", args.Entry.Value);
+    _logger.LogInformation("Enqueuing: {Data}", args.Data);
+    return Task.CompletedTask;
 });
 
-queue.Enqueued.AddHandler(async (sender, args) =>
+queue.Enqueued.AddHandler((sender, args) =>
 {
     _logger.LogInformation("Enqueued: {Id}", args.Entry.Id);
+    return Task.CompletedTask;
 });
 
-queue.Dequeued.AddHandler(async (sender, args) =>
+queue.Dequeued.AddHandler((sender, args) =>
 {
     _logger.LogInformation("Dequeued: {Id}", args.Entry.Id);
+    return Task.CompletedTask;
 });
 
-queue.Completed.AddHandler(async (sender, args) =>
+queue.Completed.AddHandler((sender, args) =>
 {
     _logger.LogInformation("Completed: {Id}", args.Entry.Id);
+    return Task.CompletedTask;
 });
 
-queue.Abandoned.AddHandler(async (sender, args) =>
+queue.Abandoned.AddHandler((sender, args) =>
 {
     _logger.LogWarning("Abandoned: {Id}", args.Entry.Id);
+    return Task.CompletedTask;
 });
 
-queue.QueueDeleted.AddHandler(async (sender, args) =>
+queue.QueueDeleted.AddHandler((sender, args) =>
 {
     _logger.LogInformation("Queue deleted");
+    return Task.CompletedTask;
 });
 ```