Fix supportsRequestAttributes for RestClientAdapter

Previously, RestClientAdapter claimed that it supports request
attributes when, in fact, it does not. This commit updates the
implementation accordingly.

See gh-32232

spring-web/src/main/java/org/springframework/web/client/support/RestClientAdapter.java

@@ -55,7 +55,7 @@ public final class RestClientAdapter implements HttpExchangeAdapter {
 
 	@Override
 	public boolean supportsRequestAttributes() {
-		return true;
+		return false;
 	}
 
 	@Override