Update codeowners for mgmt. sdk (Azure#33309)

Author: ArthurMa1978

.github/CODEOWNERS

@@ -713,7 +713,7 @@ sdk/trafficmanager/Microsoft.Azure.Management.TrafficManager/            @tmsupp
 # ######## Management Plane ########
 
 /**/*Management*/                               @fengzhou-msft @archerzz @ArcturusZhang @Yao725 @ArthurMa1978
-/**/Azure.ResourceManager*/                     @m-nash @fengzhou-msft @archerzz @ArcturusZhang @Yao725 @ArthurMa1978
+/**/Azure.ResourceManager*/                     @fengzhou-msft @archerzz @ArcturusZhang @Yao725 @ArthurMa1978
 
 # Reviewers to double check any API changes
 /sdk/**/api/                                    @KrzysztofCwalina @tg-msft