WebClient throws ClassCastException for bodyToMono(ParameterizedTypeReference)

Prior to this commit, the `WebClient` always throws a `ClassCastException`
when an error occurs in `bodyToMono(ParameterizedTypeReference)``, and
not the expected exception, as set up by `onStatus`

Issue: SPR-16025

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultWebClient.java

@@ -418,7 +418,7 @@ class DefaultWebClient implements WebClient {
 		public <T> Mono<T> bodyToMono(ParameterizedTypeReference<T> typeReference) {
 			return this.responseMono.flatMap(
 					response -> bodyToPublisher(response, BodyExtractors.toMono(typeReference),
-							mono -> (Mono<T>)mono));
+							this::monoThrowableToMono));
 		}
 
 		private <T> Mono<T> monoThrowableToMono(Mono<? extends Throwable> mono) {