Fixed errcheck issues in server/channels/api4/user_test.go (#28647)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

server/.golangci.yml

@@ -79,7 +79,6 @@ issues:
         channels/api4/system.go|\
         channels/api4/system_local.go|\
         channels/api4/team_local.go|\
-        channels/api4/user_test.go|\
         channels/api4/websocket_test.go|\
         channels/app/bot_test.go|\
         channels/app/brand.go|\