Remove settings for CERN Infrastructure

cern_integration.links.menu.yml

-cern_integration.settings:
-  title: 'CERN Infrastructure'
-  parent: system.admin_config_system
-  description: 'Access CERN Drupal infrastructure tools (e.g., database administration, file access)'
-  route_name: cern_integration.settings

cern_integration.routing.yml

-cern_integration.settings:
-  path: '/_site'
-  defaults:
-    _title: 'CERN Infrastructure'
-    _controller: '\Drupal\cern_integration\Controller\BackendController::redirect'
-  requirements:
-    _permission: 'administer site configuration'