New ENV version configs don't work on docker image: CODEX_ENV_RUBY_VERSION doesn't work

Coding with ChatGPT
1 
docker run --rm -it \
    -e CODEX_ENV_PYTHON_VERSION=3.12 \
    -e CODEX_ENV_NODE_VERSION=20 \
    -e CODEX_ENV_RUST_VERSION=1.87.0 \
    -e CODEX_ENV_GO_VERSION=1.23.8 \
    -e CODEX_ENV_SWIFT_VERSION=6.1 \
    -e CODEX_ENV_RUBY_VERSION=3.4.4 \
    -v $(pwd):/workspace/$(basename $(pwd)) -w /workspace/$(basename $(pwd)) \
    ghcr.io/openai/codex-universal:latest

(…)

ruby --version
ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [aarch64-linux-gnu]

The Ruby version line is not listed on the github page, but the ruby version can be set up on the online VMs.

Suggested fix: fix the local image to support CODEX_ENV_RUBY_VERSION like they support Swift, Python, etc.