SpringBoot Remove Jetty / Netty / Apache HttpClient checks for WebClient

With https://github.com/spring-projects/spring-framework/issues/29644 the WebClient doesn't need external dependencies anymore. If no netty / jetty / Apache HttpClient is found, it falls back to the JdkClientHttpConnector which is baked into the JDK.

At least in org.springframework.boot.test.web.reactive.server.WebTestClientContextCustomizerFactory we check for the presence of netty / jetty / apache httpclient. This check can be removed, and maybe such checks are somewhere else in the codebase.

Comment From: wilkinsona

I wonder if we should consider this a bug? Looking at the code, the checks are preventing the auto-configuration of a WebTestClient that uses the JdkClientHttpConnector.

Comment From: scottfrederick

Closing in favor of #33640.