Provide support for auto-generating pixi configuration files

This MR introduces the devtool pixi subcommand, that helps you create a draft pixi.toml configuration for your existing project. It uses a dev-profile of your choice to pin dependence versions to values used for testing in our CI. You may modify, commit (or not) the generated configuration or otherwise use it to create development environments using pixi.

assigned to @andre.anjos

changed title from Use pixi to Provide support for auto-generating pixi configuration files

changed the description

enabled an automatic merge when the pipeline for e3da23a4 succeeds

canceled the automatic merge

mentioned in commit d813a085

merged