Remove reference to jenkins_service_id

spec/migrations/delete_template_services_duplicated_by_type_spec.rb

@@ -14,11 +14,11 @@ RSpec.describe DeleteTemplateServicesDuplicatedByType do
   end
 
   it 'deletes service templates duplicated by type except the one with the lowest ID' do
-    jenkins_service_id = services.where(type: 'JenkinsService').order(:id).pluck(:id).first
+    jenkins_integration_id = services.where(type: 'JenkinsService').order(:id).pluck(:id).first
     jira_integration_id = services.where(type: 'JiraService').pluck(:id).first
 
     migrate!
 
-    expect(services.pluck(:id)).to contain_exactly(jenkins_service_id, jira_integration_id)
+    expect(services.pluck(:id)).to contain_exactly(jenkins_integration_id, jira_integration_id)
   end
 end