增加严谨的using释放，防止出现多个连接和多个channel的情况。

Author: 欧俊

.github/workflows/dotnetcore.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 3.1.100
+        dotnet-version: 5.0.301
     - name: Get tag
       id: tag
       uses: dawidd6/action-get-tag@v1

src/RabbitMQ.EventBus.AspNetCore/DefaultRabbitMQEventBus.cs

@@ -128,7 +128,7 @@ public void Subscribe(Type eventType, string type = ExchangeType.Topic)
                     channel.QueueBind(queue, attr.Exchange, attr.RoutingKey, null);
                     channel.BasicQos(0, _persistentConnection.Configuration.PrefetchCount, false);
                     subscribes[onlyKey] = channel;
-                    EventingBasicConsumer consumer = new EventingBasicConsumer(channel);
+                    EventingBasicConsumer consumer = new(channel);
                     consumer.Received += async (model, ea) =>
                     {
                         string body = Encoding.UTF8.GetString(ea.Body.ToArray());