pixi build: redundancy betweem dependencies and run-dependencies

[hadim]

At hadim/feedrattler#1, I have a few places where my package deps are redundant in pyproject.toml

• project.dependencies: pypi deps
• tool.pixi.dependencies: the "default" pixi feature
• tool.pixi.package.run-dependencies: conda deps used during package building

What do you think about an option to tell tool.pixi.package.run-dependencies to re-use the deps of a feature? And why not doing the same for host-dependencies?

[tool.pixi.package]
run-dependencies-from-feature = "default"
host-dependencies-from-feature = "dev"