refactor(types): remove dead catch-all clauses unreachable per success typing

lib/mv_web/live/group_live/show.ex

@@ -836,12 +836,6 @@ defmodule MvWeb.GroupLive.Show do
     end
   end
 
-  defp perform_add_members(socket, _group, _member_ids, _actor) do
-    {:noreply,
-     socket
-     |> put_flash(:error, gettext("No members selected."))}
-  end
-
   defp handle_successful_add_members(socket, group, actor) do
     socket = reload_group(socket, group.slug, actor)