Read the `build-system.requires` during pixi init in some way

[olivier-lacroix]

During pixi init from a pyproject.toml, it would be nice if pixi read the build-system.requires in some way, and maybe created a 'build' environment that would be used to build python packages

Originally posted by @pavelzw in #1084 (comment)

[tdejager]

Sure, but then we also need to support no build isolation, so that uv actually uses that environment, and not solves its own and hence would never use the conda resolved one: #1124

[ruben-arts]

@tdejager Would the now be able to be introduced as well? Since we now have no-build-isolation.

[tdejager]

Yes, but we would need to either install them as pypi dependencies giving you a chicken and egg problem, as it might be part of the default prefix.

or we need to interpret them as PyPI dependencies which part of a bigger feature I suppose.