[css-2022] Defer to Infra on definition of User Agent

Author: fantasai

css-2022/Overview.bs

@@ -87,7 +87,7 @@ What is CSS?</h3>
 			A user is a person who interacts with a user agent
 			to view, hear, or otherwise use the document.
 
-		<dt><dfn lt="user agent | UA">User Agent (UA)</dfn>
+		<dt><dfn noexport lt="user agent | UA">User Agent (UA)</dfn>
 		<dd>
 			A user agent is any program that interprets a document
 			and its associated [=style sheets=]