This commit warns developers about the fact that plugging RSocket into
an existing web server is only possible with Reactor Netty web servers.
RSocket itself is using Reactor Netty, so this is why we can plug an
RSocket over websocket handler in an existing Reactor Netty handler.

This feature is not possible with other web servers, as existing APIs do
not make that possible.

Fixes gh-17494

Closes gh-18265

After a change in Spring Framework (see
spring-projects/spring-framework#23314), the `RouteMatcher` to be used
with the RSocket infrastructure is configured on the `RSocketStrategies`
directly.

This commit moves the auto-configuration of the
`PathPatternRouteMatcher` from the message handling parts to the RSocket
strategy one.

Closes gh-17571

* gh-16091:
  Polish "Support zip64 jars"
  Support zip64 jars

Closes gh-16091

See gh-16091

See gh-16091

Closes gh-17234

* pr/18288:
  Fix a broken Asciidoctor syntax

Closes gh-18288

Along the way, this commit also fixes a typo.

See gh-18288

Fixes gh-18278

Closes gh-17008

Closes gh-18283

* pr/18270:
  Fix pre-defined logging group documentation

Closes gh-18270

See gh-18270

* pr/18281:
  Polish

Closes gh-18281

See gh-18281

Closes gh-18277

Closes gh-17008

Prior to this commit, Spring Boot would use `Schedulers.elastic()` when
required to process blocking tasks in a reactive environment.
reactor/reactor-core#1804 introduced a new scheduler,
`Schedulers.boundedElastic()` that behaves quite similarly but:

* will limit the number of workers thread
* will queue tasks if no worker thread is available and reject them is
the queue is exceeds a limit

This allows Spring Boot to schedule blocking tasks as before and allows
greater flexibility.

Fixes gh-18269
See gh-18276

Closes gh-17435

* gh-11779:
  Use try-with-resources in HttpTunnelPayload

Closes gh-11779

See gh-11779

Closes gh-18274

Closes gh-18242

* gh-18262:
  Add Graal checks ahead of some interactions with ClassLoader methods

Closes gh-18262

See gh-18262

Closes gh-18267

Closes gh-18178

* gh-18249:
  Fix typos in HealthContributors definition

Closes gh-18249

See gh-18249

* gh-18248:
  Remove duplicated row from HealthIndicators table

Closes gh-18248

See gh-18248

Previously, Reactor Netty was the only embedded server that enabled
H2C by default. This commit updates the factory to only enable HTTP/2
when SSL has also been configured, aligning it with Jetty, Tomcat,
and Undertow.

If H2C is required, it can be enabled using a NettyServerCustomizer:

@Bean
NettyServerCustomizer h2cCustomizer() {
    return (httpServer) ->
           httpServer.protocol(HttpProtocol.HTTP11, HttpProtocol.H2C);
}

Closes gh-17867

Closes gh-16289

Closes gh-18239

This commit makes sure that any subsequent call on addProtocolResolver
on the context will impact the ResourceLoader implementation that
DevTools sets on the context.

This makes sure that any custom ProtocolResolver that is set later in
the lifecycle is taken into account.

Closes gh-17214