fix: remove duplicated word in use-server

Author: nayounsang

src/content/reference/rsc/use-server.md

@@ -5,7 +5,7 @@ titleForTitleTag: "'use server' directive"
 
 <RSC>
 
-`'use server'` is for use with [using React Server Components](/learn/start-a-new-react-project#bleeding-edge-react-frameworks).
+`'use server'` is for use with [React Server Components](/learn/start-a-new-react-project#bleeding-edge-react-frameworks).
 
 </RSC>