[libcxx-commits] [libcxx] [libc++] Bump base image version to most recent (PR #208776)

[Louis Dionne via libcxx-commits]

ldionne wrote:

@boomanaiden154 @cmtice Would it be possible to deploy this to the `llvm-premerge-libcxx-runners` workers?

We're currently using the `llvm-premerge-libcxx-next-runners` group already, so we should deploy to the "non-next" group and flip over in a PR once ready.

https://github.com/llvm/llvm-project/pull/208776