[MM-61761] Fix errcheck issues in channels/app/platform/cluster_handlers.go (#29302)

* Fixed errcheck issues

* fixed issues

* fixed issues

* Fix merge conflict

* fix code

server/.golangci.yml

@@ -98,7 +98,6 @@ issues:
         channels/app/migrations.go|\
         channels/app/permissions.go|\
         channels/app/permissions_test.go|\
-        channels/app/platform/cluster_handlers.go|\
         channels/app/platform/helper_test.go|\
         channels/app/platform/license.go|\
         channels/app/platform/link_cache.go|\