Setup amip+CN configuration

[blimlim]

1. Summary:

This PR sets up the carbon-nitrogen only version of the amip configuration. It uses a copy of the restart from the dev-preindustrial+concentrations+CN configuration, with the restart year reset to 1978.
Why was this done?
CN variants of each configuration are required

2. Issues Addressed:

• Create carbon nitrogen only configurations #495

3. Dependencies (e.g. on payu, or model)

This change requires changes to (note pull request(s) where relevant):

• workflow manager (payu):
• model deployment (ACCESS-ESM1.6):
• model component or library dependency:
• input workflow:

4. Ad-hoc Testing

What ad-hoc testing was done? How are you convinced this change is correct (plots are good)?

5. CI Testing

• !test repro has been run

6. Reproducibility

Is this reproducible with the previous commit? (If not, why not?)

• Yes
• No - !test repro commit has been run.

The new restart and change in cable mode will change answers

7. Performance

Has the model performance (say, throughput of model-years/wall-day) changed?

• Yes
• No
• N/A (if selected, please add a brief explanation why performance testing is not necessary for this PR)

As this PR sets up a new configuration, it does not affect the performance of the existing configurations.

If yes, provide the numbers from your testing. Is the performance better or worse?

8. Manifests

Have you changed the executable, the input files and/or the restart files?

• Yes
• No

If yes, have you updated the manifests?

• Yes
• No

To update the manifests, run payu setup (in a cloned copy of your feature branch) with reproducibility tests turned off:

manifest:
  reproduce:
    exe: false
    input: false
    restart: false
runlog:
  enable: false

Then commit the newly created manifest files (under manifests/) only to the branch for this PR.

9. Documentation

Is the documentation updated?

• Yes
• N/A

10. Merge Strategy

• Merge commit
• Rebase and merge
• Squash

[blimlim]

!test repro commit

[github-actions]

❌ The Bitwise Reproducibility Check Failed ❌

When comparing:

• 495-amip+CN (checksums created using commit 3315152), against
• dev-amip+CN (checksums in commit e51c3a3)

🔧 The new checksums will be committed to this PR, if they differ from what is on this branch.

Further information

The experiment can be found on Gadi at /scratch/tm70/repro-ci/experiments/access-esm1.6-configs/3315152872965f378c5c0f38ba6e872e858a6e65, and the test results at https://github.com/ACCESS-NRI/access-esm1.6-configs/runs/64923941289.

The checksums generated by this !test command are found in the testing/checksum directory of https://github.com/ACCESS-NRI/access-esm1.6-configs/actions/runs/22422598304/artifacts/5664370378.

The checksums compared against are found here https://github.com/ACCESS-NRI/access-esm1.6-configs/tree/e51c3a35efbb7535192d4fb68af455420fdf1d42/testing/checksum

Test summary:
❌ test_repro_historical
✅ test_repro_determinism

[MartinDix]

OK