Remove redundant service template specs

Services templates are deprecated, and we now only show
active service templates. In other words,
users cannot activate new service templates.

This commit removes all redundant specs for service templates.

spec/features/admin/admin_settings_spec.rb

@@ -249,35 +249,6 @@ RSpec.describe 'Admin updates settings' do
         expect(page).to have_content "Application settings saved successfully"
         expect(current_settings.hide_third_party_offers).to be true
       end
-
-      it 'change Slack Notifications Service template settings', :js do
-        first(:link, 'Service Templates').click
-        click_link 'Slack notifications'
-        fill_in 'Webhook', with: 'http://localhost'
-        fill_in 'Username', with: 'test_user'
-        fill_in 'service[push_channel]', with: '#test_channel'
-        page.check('Notify only broken pipelines')
-        page.select 'All branches', from: 'Branches to be notified'
-
-        check_all_events
-        click_button 'Save changes'
-
-        expect(page).to have_content 'Application settings saved successfully'
-
-        click_link 'Slack notifications'
-
-        expect(page.all('input[type=checkbox]')).to all(be_checked)
-        expect(find_field('Webhook').value).to eq 'http://localhost'
-        expect(find_field('Username').value).to eq 'test_user'
-        expect(find('[name="service[push_channel]"]').value).to eq '#test_channel'
-      end
-
-      it 'defaults Deployment events to false for chat notification template settings', :js do
-        first(:link, 'Service Templates').click
-        click_link 'Slack notifications'
-
-        expect(find_field('Deployment')).not_to be_checked
-      end
     end
 
     context 'Integration page', :js do

spec/features/admin/services/admin_activates_prometheus_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe 'Admin activates Prometheus', :js do
-  let(:admin) { create(:user, :admin) }
-
-  before do
-    sign_in(admin)
-    gitlab_enable_admin_mode_sign_in(admin)
-
-    visit(admin_application_settings_services_path)
-
-    click_link('Prometheus')
-  end
-
-  it 'activates service' do
-    check('Active')
-    fill_in('API URL', with: 'http://prometheus.example.com')
-    click_button('Save changes')
-
-    expect(page).to have_content('Application settings saved successfully')
-  end
-end

spec/views/admin/services/index.html.haml_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe 'admin/services/index.html.haml' do
-  before do
-    assign(:services, build_stubbed_list(:service, 1))
-    assign(:existing_instance_types, [])
-  end
-
-  context 'user has not dismissed Service Templates deprecation message' do
-    it 'shows the message' do
-      allow(view).to receive(:show_service_templates_deprecated?).and_return(true)
-
-      render
-
-      expect(rendered).to have_content('Service Templates will soon be deprecated.')
-    end
-  end
-
-  context 'user has dismissed Service Templates deprecation message' do
-    it 'does not show the message' do
-      allow(view).to receive(:show_service_templates_deprecated?).and_return(false)
-
-      render
-
-      expect(rendered).not_to have_content('Service Templates will soon be deprecated.')
-    end
-  end
-end