[libcxx-commits] [libcxx] [llvm] [libc++] Simplify the workflow for updating CI docker images (PR #186456)

[Aiden Grossman via libcxx-commits]

https://github.com/boomanaiden154 commented:

The original idea was that `BASE_IMAGE_VERSION` (or whatever the earlier equivalent of it was) could be set to something like `base` which would just build everything from source including the base image. That way we only actually build from a GHCR image if we need to (e.g., we need to bump the Github runner version without touching anything else).

https://github.com/llvm/llvm-project/pull/186456