[release tool]: merge staging pull requests through the tool itself

Currently it is unclear what should be used to merge staging pull requests. We should just let the release tool merge the PR as it knows exactly where the PR should go into. The merge tool would rely on target labels which might not work temporarily e.g. when branching-off a feature freeze.

We should either merge automatically once the PR is approved + checks are passing, or we just add a double-prompt that can be submitted to manually start the merging (useful in case the PR checks are not significant as in COMP and FW - though worth noting that this could be done through a configuration as well in `.ng-dev`.)

The cherry-pick PRs should be merged automatically based on our discussion

Comienza localizando el flujo de merge de pull requests de staging de la herramienta de release y revisando la configuración `.ng-dev` mencionada en el issue. Compara el merge automático con la doble confirmación propuesta y las opciones de configuración, incluido el comportamiento de cherry-pick indicado. Se considera terminado cuando la política de merge para los casos descritos de staging y cherry-pick esté decidida e implementada.

Escrito por el modelo de indexación a partir del texto del issue.