Move CI from `access-om2-configs`/`reproducibility` into this repository

[CodeGat]

Background

In order to add ACCESS-ESM1.5 config CI (related issue here: https://github.com/ACCESS-NRI/access-esm1.5-configs/issues/15), we need to generify and consolidate the existing access-om2-configs workflows (found here) as well as the reproducibility workflows (found here).

Tasks

• [x] access-om2-configs: Move ci.schema.json to ACCESS-NRI/schema and use the associated action in ACCESS-NRI/schema to validate each model-configs ci.json. See PRs https://github.com/ACCESS-NRI/access-om2-configs/pull/116 and https://github.com/ACCESS-NRI/schema/pull/32
• [x] access-om2-configs: Move pr-*.yml, schedule-*.yml workflows to this repository. See https://github.com/ACCESS-NRI/access-om2-configs/pull/117 and https://github.com/ACCESS-NRI/model-config-tests/pull/24
• [x] access-om2-configs: Open a PR that makes all call-pr-*.yml workflows reference the above moved workflows. Also add calls to pr-2-confirm.yml and schedule-*.yml workflows. Important: This change will have to be reflected in all config branches in access-om2-configs - release-* and dev-*, as well as main! See https://github.com/ACCESS-NRI/access-om2-configs/pull/117 for changes in main, changes will need to be force-propagated to every branch by an admin
• [x] reproducibility: Move checks.yml and generate-initial-checksums.yml to this repository, consider archiving/moving this repo (ask @aidanheerdegen, issue here ). See https://github.com/ACCESS-NRI/reproducibility/pull/29 and https://github.com/ACCESS-NRI/model-config-tests/pull/26
• [x] model-config-tests: Make sure that there is no model-config-specific logic in the workflows in this repository
• [x] model-config-tests: Check GitHub Environment variables and links
• [x] model-config-tests: Update the README.md and devdocs
• [x] model-config-template: Create this repository and populate it with a barebones version of the changes in https://github.com/ACCESS-NRI/access-om2-configs/pull/117 as well as a HOW-TO guide. See https://github.com/ACCESS-NRI/model-configs-template/pull/1
• [x] Test this updated workflow on the test organisation

References old issue https://github.com/ACCESS-NRI/reproducibility/issues/8 Requires https://github.com/ACCESS-NRI/access-om2-configs/issues/109 (pinging @jo-basevi so she knows what's coming next up)

[CodeGat]

Closing as all the requisite tasks are done. Thanks for the reviews, @jo-basevi !