reverted:
--- b/core/modules/migrate_drupal_ui/migrate_drupal_ui.links.menu.yml
+++ /dev/null
@@ -1,19 +0,0 @@
-migrate_drupal_ui.migration:
-  title: 'Site Upgrade'
-  parent: system.admin_config_development
-  description: 'Upgrade content, structure and configuration from older Drupal versions.'
-  route_name: migrate_drupal_ui.migration
-
-migrate_drupal_ui.upgrade:
-  title: 'Upgrade'
-  parent: migrate_drupal_ui.migration
-  description: 'Begin the upgrade.'
-  route_name: migrate_drupal_ui.upgrade
-  weight: -1
-
-migrate_drupal_ui.log:
-  title: 'Upgrade log'
-  parent: migrate_drupal_ui.migration
-  description: 'View upgrade log.'
-  route_name: migrate_drupal_ui.log
-  weight: 0