Fix typo in RSocket reference documentation

This commit fixes a typo in a Java code snippet of
the RSocket reference documentation.

Closes gh-23762

src/docs/asciidoc/rsocket.adoc

@@ -689,7 +689,7 @@ you need to share configuration between a client and a server in the same proces
 
 		@Bean
 		public RSocketStrategies rsocketStrategies() {
-			retrun RSocketStrategies.builder()
+			return RSocketStrategies.builder()
 				.encoders(encoders -> encoders.add(new Jackson2CborEncoder))
 				.decoders(decoders -> decoders.add(new Jackson2CborDecoder))
 				.routeMatcher(new PathPatternRouteMatcher())