Dependencies installation order.

[LittleCoinCoin]

Version 1.2.0 of the packages schema currently allows to declare different types of dependencies. In particular, it allows for system dependencies. It is highly possible that some of these are actually necessary to enable the compilation of other dependencies (e.g. python ones).
Hence, we must find a way to encode user-side installation order preferences.
I don't know at which level this should be, however. For example, it doesn't make sense to put installation order preferences within dependency types because it's the job of each package manager to decide in which order to instal these. However, order in between dependency types seems relevant.
Should we add flexibility and allow different steps of installation for groups of dependencies of different types? For example
Dependencies:

• Step1:
  • system:
    • system dep 1
    • system dep 2
  • python:
    • python dep 1
    • python dep 2
  • hatch:
  • docker:
• Step 2:
  • docker
  • python
    ... and so on

?