ci: test interesting rust-gpu revs

[Firestar99]

• add infrastructure to test rust-gpu revs, not just releases
  • includes overwriting glam version in ci
• see ci file on why certain revs were chosen. Primarily:
  • target spec changes
  • glam semver breakage due to abi: Make glam types abi layout match CPU rust-gpu#380
• on ci 0.8.0 and 0.9.0 breakages
  • dep change infra only allows changing deps in the shader crate, not the rustc_codegen_spirv compile, so this is insufficient to fix it
  • see https://github.com/Rust-GPU/cargo-gpu/actions/runs/20230850709 succeeding with "the hack"

[tombh]

Really nice.

Once I saw this it made a bit more sense:

So it's #128 that should make it look like that?

[Firestar99]

Na, it's all blocked on

• spirv-std 0.8.0 & 0.9.0 fail to compile rustc-codegen-spirv #123

(still don't have access to spirt on crates, cause the owner is currently unreachable...)