How to use a template for internal environments?

[plu-bgl]

I saw in #1600 that the internal test environment (and I guess the other internal environments too) do not inherit from default. Is there a way to make them use a template? I tried to set template = "default" or template = "base" for the hatch-test environment, but it keeps ignoring the dependencies specified in default or base.

I also do not understand why this default behavior is. You can disable inheritance if you use template = "hatch-test". There is already a way to opt-out for inheritance, but there is no way to opt-in anymore.