errcheck issues fixed (#28572)

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

server/.golangci.yml

@@ -93,7 +93,6 @@ issues:
         channels/api4/user.go|\
         channels/api4/user_test.go|\
         channels/api4/webhook_test.go|\
-        channels/api4/websocket_test.go|\
         channels/app/admin.go|\
         channels/app/app_test.go|\
         channels/app/authorization_test.go|\