Fix Javadoc build for new RSocket dependencies

See gh-16021

spring-boot-project/spring-boot-docs/pom.xml

@@ -315,6 +315,16 @@
 			<artifactId>reactor-netty</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>io.rsocket</groupId>
+			<artifactId>rsocket-core</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>io.rsocket</groupId>
+			<artifactId>rsocket-transport-netty</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>io.prometheus</groupId>
 			<artifactId>simpleclient_pushgateway</artifactId>