composer/plugin/drupal-10-scaffold#1 Generally allow oomphinc/composer-installers-extender in pipelines

#16 Create new mixin to merge a branch, use that in various places and ensure composer packages to always merge in the release stage

composer/plugin/drupal-development-environment#13 Add support for extended composer audit, disabled by default

The Drupal pipeline validation moved into the .pre stage
The Drupal check for updates moved to test stage

Always configure composer to allow drupal/core-vendor-hardening plugin as it might be left over in the cache