Release docker img

[KuuCi]

Updates the release process to also create a docker image upon hitting a tag with v*. Some parts are commented out for testing and will be reintroduced upon approval.

This was triggered off of this branch:
https://github.com/mosaicml/llm-foundry/actions/runs/11022339619/job/30611648283

As can be seen in the image building process, it properly clones the correct ref + repo along with all of the other installs.

[KuuCi]

https://github.com/mosaicml/llm-foundry/actions/runs/11041925214

^updated to use original dockerfile

[mvpatel2000]

LGTM, @dakinggg plz also review

[KuuCi]

Took me 20 commits to realize I was testing (crying internally):
mcli interactive --max-duration 1 --gpus 1 --tmux --cluster r1z2 mosaicml/llm-foundry:release_release-docker-img
instead of
mcli interactive --max-duration 1 --gpus 1 --tmux --cluster r1z2 --image mosaicml/llm-foundry:release_release-docker-img