Base PR-Based Repro-Testing Workflow

[CodeGat]

This PR is a slimmed-down variant of the now-closed #122 PR.

This PR contains only the base workflow as specified in access-nri/model-configs-template, similar to the existing access-[om2|esm1.5]-configs repositories. This is so we can merge in functionality that is set in stone, with additions that require extra time/thought to come later.

References #120

[anton-seaice]

This looks good Tommy - is it ready to go ?

[CodeGat]

Hey @anton-seaice - it is ready to go. It's the base PR workflow shared between all the other access-*-configs repos we have, so it doesn't yet have the docs bit that you require. I still think it's worth incrementally adding the bits that are set in stone, just so we don't have a 100-year PR while other bits are being hashed out.

There is a follow-up PR here for adding the !test comment command so you can test/commit checksums in non-release-* branches, I'm just testing it in my own org first.

[anton-seaice]

Thanks Tommy!