Qute getting started guide - remove outdated section about async APIs

- resolves quarkusio#28230

(cherry picked from commit 6c612ac)

docs/src/main/asciidoc/qute.adoc

@@ -498,29 +498,6 @@ public class ReportGenerator {
 <2> Use the `@Scheduled` annotation to instruct Quarkus to execute this method on the half hour. For more information see the xref:scheduler.adoc[Scheduler] guide.
 <3> The `TemplateInstance.render()` method triggers rendering. Note that this method blocks the current thread.
 
-== Reactive and Asynchronous APIs
-
-Templates can be rendered as a `CompletionStage<String>` (completed with the rendered output asynchronously) or as `Publisher<String>` containing the rendered chunks:
-
-[source, java]
-----
-CompletionStage<String> async = template.data("name", "neo").renderAsync();
-Publisher<String> publisher = template.data("name", "neo").publisher();
-----
-
-In the case of a `Publisher`, the template is rendered chunk by chunk following the requests from the subscriber.
-The rendering is not started until a subscriber requests it.
-The returned `Publisher` is an instance of `io.smallrye.mutiny.Multi`.
-
-It is possible to create an instance of `io.smallrye.mutiny.Uni` as follows:
-
-[source, java]
-----
-Uni<String> uni = Uni.createFrom().completionStage(() -> template.data("name", "neo").renderAsync());
-----
-
-In this case, the rendering only starts once the subscriber requests it.
-
 == Qute Reference Guide
 
 To learn more about Qute, please refer to the xref:qute-reference.adoc[Qute reference guide].