Add leaderboard controller spec to check for errors for disabled component
user
```ruby
# frozen_string_literal: true
require 'rails_helper'

RSpec.describe Course::LeaderboardsController, type: :controller do
  let!(:instance) { create(:instance) }

  with_tenant(:instance) do
    let!(:user) { create(:administrator) }
    let!(:course) { create(:course) }

    before { sign_in(user) }

    describe '#show' do
      before do
        allow(controller).to receive_message_chain('current_component_host.[]').and_return(nil)
      end
      subject { get :show, course_id: course }
      it 'raises an component not found error' do
        expect { subject }.to raise_error(ComponentNotFoundError)
      end
    end
  end
end
```
assistant