References issue ACCESS-NRI/build-cd#121 and detailed PR ACCESS-NRI/build-cd#218

Background

This update to the deployment infrastructure allows deployment to multiple different HPC systems (or the same one but a different spack instance) in parallel.

Some of the major changes relevant to a model deployment repository include:

• spack.yaml: A new way to format spack.yaml so that even if there are differences in HPC architecture or variants, we can still deploy using a single spack.yaml. See https://github.com/ACCESS-NRI/ACCESS-OM2/blob/ce5fdd27badabcbff464d50fcdc4df8e80a74123/spack.yaml for an example. You can still deploy using the traditional spack.specs[0] method.

• Choose Where To Deploy Pre/Releases: Model Deployment Repositories can now set the repo-level vars.PRERELEASE_DEPLOYMENT_TARGETS/vars.RELEASE_DEPLOYMENT_TARGETS to choose which HPCs they deploy to. This is of the form of a space-separated list of GitHub Environments (minus any potential Prerelease bit), for example: vars.PRERELEASE_DEPLOYMENT_TARGET == Gadi Setonix, vars.RELEASE_DEPLOYMENT_TARGET == Gadi.

• Updated Deployment Comments/Release Notes: Since we can deploy to multiple targets, we've had to rework the style of the deployment comments/notes. Example of Release Notes here: Make release Job Take Inputs From Multi-Target Deployments build-cd#200 (comment) and Comment here: Fix Up Multi-Target TODOs build-cd#199 (comment)

Prerequisites for Merging

• Add values for repo-level vars.[PRE]RELEASE_DEPLOYMENT_TARGETS
• Update repo-level vars.SPACK_YAML_SCHEMA_VERSION to 1-0-4
• Update entrypoints to @v4, update ci.yml pr-closed jobs model input to root-sbd, update cd.yml cd job permissions.pull-requests:write (This PR!)
• Add GitHub Environment for Releases with name SUPERCOMPUTER Release rather than SUPERCOMPUTER