Simplify .NET worker execution example

references/dotnet/dotnet.md

@@ -59,20 +59,13 @@ using Temporalio.Worker;
 
 var client = await TemporalClient.ConnectAsync(new("localhost:7233"));
 
-using var tokenSource = new CancellationTokenSource();
-Console.CancelKeyPress += (_, eventArgs) =>
-{
-    tokenSource.Cancel();
-    eventArgs.Cancel = true;
-};
-
 using var worker = new TemporalWorker(
     client,
     new TemporalWorkerOptions("my-task-queue")
         .AddWorkflow<GreetingWorkflow>()
         .AddAllActivities(new MyActivities()));
 
-await worker.ExecuteAsync(tokenSource.Token);
+await worker.ExecuteAsync(() => Task.Delay(Timeout.Infinite));
 ```
 
 **Start the dev server:** Start `temporal server start-dev` in the background.