Skip CSRF protection in Generic Alerts Endpoint

Public API endpoints doesn't need to have CSRF protection

ee/app/controllers/projects/alerting/notifications_controller.rb

@@ -5,6 +5,7 @@ module Projects
     class NotificationsController < Projects::ApplicationController
       respond_to :json
 
+      skip_before_action :verify_authenticity_token
       skip_before_action :project
 
       prepend_before_action :repository, :project_without_auth

ee/spec/controllers/projects/alerting/notifications_controller_spec.rb

@@ -10,6 +10,10 @@ describe Projects::Alerting::NotificationsController do
     let(:service_response) { ServiceResponse.success }
     let(:notify_service) { instance_double(Projects::Alerting::NotifyService, execute: service_response) }
 
+    around do |example|
+      ForgeryProtection.with_forgery_protection { example.run }
+    end
+
     before do
       allow(Projects::Alerting::NotifyService).to receive(:new).and_return(notify_service)
     end