[BUG] Linux and macOS Python 3.10 builds are now failing

[lohedges]

The Linux Python 3.10 build has been timing out or taking ages for quite a while now and, as of this week, macOS Python 3.10 has also joined it. It might be time that we consider dropping support for Python 3.10, although I don't think 3.12 works on macOS yet. (Core dependencies are probably okay, but not the full set.)

One other option is to try switching to pixi and rattler-build, which seems to be what all the cool kids are using these days. My concern is that we would no longer be able to use our requirements file approach with the appropriate dependencies then injected into the conda template file. Rattler uses standard YAML formatting for the recipe, so platform dependent requirements are handled via conditional logic, rather than conda-build specfiic selectors. I might just translate things on a feature branch to see if it helps with the build issues, then think about a more general porting strategy if it works.