Update rabbitmq version CI

The test StreamShouldReadTheAmqp10PropertiesMessages now works correctly due of
rabbitmq/rabbitmq-server#7001 so we removed the workaround
for the issue

Signed-off-by: Gabriele Santomaggio <[email protected]>

Author: Gsantomaggio

.ci/versions.json

@@ -1,4 +1,4 @@
 {
   "erlang": "25.2",
-  "rabbitmq": "3.11.7"
+  "rabbitmq": "3.11.9"
 }

Tests/FromToAMQPTests.cs

@@ -351,11 +351,7 @@ public async void StreamShouldReadTheAmqp10PropertiesMessages()
 
         new Utils<Message>(_testOutputHelper).WaitUntilTaskCompletes(tcs);
         var result = tcs.Task.Result;
-        // Why do we need result.Data.Contents.ToArray()[5..]? 
-        // Because of https://github.com/rabbitmq/rabbitmq-server/issues/6937 
-        // When it will be fixed we can remove the [5..]
-        // For the moment we leave it as it is because it is not a problem for the client
-        Assert.Equal("msg from amqp 1.0", Encoding.UTF8.GetString(result.Data.Contents.ToArray()[5..]));
+        Assert.Equal("msg from amqp 1.0", result.AmqpValue);
         await consumer.Close();
         await system.DeleteStream(stream);
         await system.Close();