Keep track of Codespaces and VSCode Dev Containers GPU support

[tbenthompson]

Currently the dev containers and Codespaces GPU support is super messy and problematic:

• there's no devcontainers base image for cuda
• --gpus all is necessary for the dev container extension but will break Codespaces. There's a PR to work on this: GPU requirement and auto-detect NVIDIA extensions devcontainers/cli#173
• the driver versions are unstable!

[tbenthompson]

A PR creating a CUDA devcontainer: microsoft/vscode-dev-containers#1176

Seems blocked and likely to be replaced by Microsoft efforts that are blocked by the gpu requirements PR above.

[tbenthompson]

GitHub roadmap issue tracking GPUs in Actions runners: github/roadmap#505

[tbenthompson]

Seems like Dev Containers support GPUs now: https://github.com/microsoft/vscode-docs/blob/main/remote-release-notes/v1_74.md

I'm not sure if this feature works with Codespaces or not but we should try it.

[tbenthompson]

Done with #291