Accept repository_update_events in SystemHooks API

This adds support for the `repository_update_events` argument in the
SystemHooks API.

https://gitlab.com/gitlab-org/gitlab/-/issues/331259

Changelog: added

lib/api/system_hooks.rb

@@ -31,6 +31,7 @@ module API
         optional :push_events, type: Boolean, desc: "Trigger hook on push events"
         optional :tag_push_events, type: Boolean, desc: "Trigger hook on tag push events"
         optional :merge_requests_events, type: Boolean, desc: "Trigger hook on tag push events"
+        optional :repository_update_events, type: Boolean, desc: "Trigger hook on repository update events"
         optional :enable_ssl_verification, type: Boolean, desc: "Do SSL verification when triggering the hook"
       end
       post do

spec/requests/api/system_hooks_spec.rb

@@ -81,6 +81,7 @@ RSpec.describe API::SystemHooks do
       expect(json_response['push_events']).to be false
       expect(json_response['tag_push_events']).to be false
       expect(json_response['merge_requests_events']).to be false
+      expect(json_response['repository_update_events']).to be true
     end
 
     it 'sets explicit values for events' do
@@ -92,7 +93,8 @@ RSpec.describe API::SystemHooks do
           enable_ssl_verification: false,
           push_events: true,
           tag_push_events: true,
-          merge_requests_events: true
+          merge_requests_events: true,
+          repository_update_events: false
         }
 
       expect(response).to have_gitlab_http_status(:created)
@@ -100,6 +102,7 @@ RSpec.describe API::SystemHooks do
       expect(json_response['push_events']).to be true
       expect(json_response['tag_push_events']).to be true
       expect(json_response['merge_requests_events']).to be true
+      expect(json_response['repository_update_events']).to be false
     end
   end