Move spack-config into config/settings.json

[CodeGat]

Background

We've decided that we don't want model developers to be able to tweak the spack-config setting in their model deployment repositories config/versions.json file.

Thus, in this PR, we move that functionality into our protected config/settings.json file, as well as removing any reading/modification of spack-config from the deploy-*.yml and undeploy-*.yml workflow, as it should all be done in settings-*.yml.

This also means that we need to update the schema for deployment repos config/versions.json file - see ACCESS-NRI/schema#36

Important Notes

NOTE: This willl require that all the config/version.jsons in all model deployment repos remove the spack-config section, and update the CONFIG_VERSIONS_SCHEMA_VERSION to 3-0-0.

NOTE: This PR will fail deployment settings validation because it it using the @main version of the action rather than the PR version of the action. Independent validation of the config/settings.json has taken place - see https://github.com/codegat-test-org/test/actions/runs/10917132371/job/30299846971

This PR

In this PR:

• validate-repo-version: update README instructions. See f68b53d
• Remove reading/modification of spack-config from [un]deploy-2-*.yml workflows. See 26d0044
• Update config/settings.json and config/settings.schema.json to allow for spack-config. See 24e1cfc
  • Update spack checks in validate-deployment-settings action since config/settings.schema.json was updated. See 6b429c4
  • Add new spack-config checks in `validate-deployment-settings. See ab5d062
• settings-*.yml workflow now deploys changes to spack-config. See f5d3417

Closes #123

[CodeGat]

^ Sorry, you two are automatically listed as reviewers because I modified the config/settings.json file, which you are CODEOWNERS.

[aidanheerdegen]

LGTM