Introduce skid_steer as a new way to load assets

[patowen]

This is a relatively significant refactor of Hypermine, switching up asset loading to use a new library called "skid_steer".

It introduces the following changes:

• A custom AssetLoader type is added to drive asset loading, acting as the glue between skid_steer and Hypermine. This completely replaces the old loader module.
• All uses of the staging buffer and transfer module from the temporary lahar_deprecated module have been replaced with a vendored growable_ring implementation from @Ralith, and a ParallelQueue from the current version of lahar. This allows us to finally remove the lahar_deprecated module, a task that I had hoped to do years ago.
• PNG loading and GLTF loading, the only two processes that depended on the old Loader, have been migrated to the new AssetLoader.
• File-processing (reading PNGs and GLBs) and Vulkan-wrangling (making Vulkan calls) have been fully separated, with all data being read into memory in a convenient form before being passed into Vulkan data structures.
• To support some of the above changes, some data has been moved around, including the addition of a new ShaderData struct to pass around global data used for rendering.

[patowen]

When separating out gtlf-reading logic with Vulkan wrangling, I had decided to remove the functionality that uses cmd_clear_color_image to fill the 1x1 image with a specified color, in favor of just specifying the color directly.

However, this requires a conversion from f32 color to SRGB, which you might have opinions on how to do. One option could be to import something like https://crates.io/crates/palette (although you might have a preferred crate for this). Given that we might want to do more in the future, I don't think we want to hardcode the gamma correction formula.

[patowen]

See https://github.com/Ralith/hypermine/pull/515/changes/BASE..0908719a3be8e59af41e30e075cbe97f0001cf17#r3834892686.

I deliberately kept the lint failing due to this line so that I wouldn't forget to address this.