Update localAddress Javadoc in WebSocketSession

Closes gh-34304

spring-websocket/src/main/java/org/springframework/web/socket/WebSocketSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -73,6 +73,12 @@ public interface WebSocketSession extends Closeable {
 
 	/**
 	 * Return the address on which the request was received.
+	 * <p><strong>Note:</strong> The localAddress is not always possible to access,
+	 * which is the case with the Standard WebSocket client. In 6.2.x
+	 * {@link org.springframework.web.socket.client.standard.StandardWebSocketClient}
+	 * returns an address based on the local host and the port of the target
+	 * address (not the same as the local port). In 7.0, the same will return
+	 * {@code null} instead.
 	 */
 	@Nullable
 	InetSocketAddress getLocalAddress();