fix some quick wins

Author: bollhals

projects/RabbitMQ.Client/client/RentedMemory.cs

@@ -68,23 +68,17 @@ internal readonly ReadOnlyMemory<byte> CopyToMemory()
             return new ReadOnlyMemory<byte>(Memory.ToArray());
         }
 
-        private void Dispose(bool disposing)
+        public void Dispose()
         {
             if (!_disposedValue)
             {
-                if (disposing && RentedArray != null)
+                if (RentedArray != null)
                 {
                     ArrayPool<byte>.Shared.Return(RentedArray);
                 }
 
                 _disposedValue = true;
             }
         }
-
-        public void Dispose()
-        {
-            Dispose(disposing: true);
-            GC.SuppressFinalize(this);
-        }
     }
 }

projects/RabbitMQ.Client/client/impl/ChannelBase.cs

@@ -1069,10 +1069,7 @@ await _confirmSemaphore.WaitAsync(cancellationToken)
 
             try
             {
-                var cmd = new BasicPublishMemory(
-                    Encoding.UTF8.GetBytes(exchange),
-                    Encoding.UTF8.GetBytes(routingKey),
-                    mandatory, default);
+                var cmd = new BasicPublish(exchange, routingKey, mandatory, default);
                 using Activity sendActivity = RabbitMQActivitySource.PublisherHasListeners
                     ? RabbitMQActivitySource.Send(routingKey, exchange, body.Length)
                     : default;