не очень понятно вот это "можно и не ставить", что оно меняет?
Weak dependencies may only be used in a package if the package still functions without the dependency present. It is acceptable, however, to create packages that have very limited functionality without adding any of its weak requirements. Weak dependencies should be used where possible to minimize the installation for reasonable use cases, especially for building virtual machines or containers that have a single purpose only and do not require the full feature set of the package.