Restructure CI tests as a single workflow

[marshallward]

This commit consolidates many of the CI tests into a single workflow. In principle, it replaces multiple builds of the model with a single workflow. In many respects, this resembles our regression suite on Gaea.

(Example: https://github.com/NOAA-GFDL/MOM6/actions/runs/14092259355)

In practice, it is only marginally faster by some metrics, and slower by others.

• Although we don't rebuild FMS and the models, we do have to set up the ubuntu environment on every stage which has a cost (at least 30s).

  If we can eliminate this overhead somehow (e.g. container?) then this method may be much faster.

• MacOS is now slower, but we are running more tests. Previously, we were only doing a small handful of them.

• Setting up the artifacts is delicate (paths, for example), and there is some overhead in transfer, but it appears to be small (<10s).

• Cleanup relies on a third-party GitHub Actions "app", which may not be supported over long term.

  Also, a failed test will not delete its artifacts. If these accumulate, then we may hit a storage limit.

  Worst case: Artifacts are wiped after 1 day. This is the minimum setting.

• Minor point: As the number of tests increase, the graph scales to fit in the same box, and the actual stages become almost unreadable without zooming in. Not really the effect I was hoping for.

Notes on MacOS (aarch64) builds:

• Disable fp-contract

  Seems like aarch64 (ARM) needs -ffp-contract=off to disable FMAs. -mno-fma is not supported!

• Optimization is reduced to -O1 for DEBUG-REPRO equivalence.

  This is only an issue in the tidal forcing, and most likely due to trigonometric function evaluation. But I can't yet see any other solution.

There are also some very minor changes to the .testing Makefile:

• Log output is now consistently set to 100 lines for all tests.

• Builtin rule flags were replaced with explicit long forms

• Empty SUFFIX: rule was added, to belabor the point.

[marshallward]

Never seen this error:

Run geekyeggo/delete-artifact@v4
Error: HttpError: Resource not accessible by integration

Might need some time or help to work out this one...

[marshallward]

The final cleanup stage needed permissions. This is what finally worked:

    permissions:
      id-token: write
      contents: write
      pull-requests: write
      repository-projects: write

The only one that I am certain is required is id-token: write. I will iterate a bit on the others and see what works. (The others may already default to write.)

[marshallward]

This was the only necessary change.

    permissions:
      id-token: write

I think this is now ready for review.

[marshallward]

Oh, I did remove the old test files, which means that the "mandatory" tests can no longer be run.

Some options (assuming this were to be accepted):

• Restore them and then remove them in a second PR.
• Change the settings, then accept the PR.
• Accept the PR with admin override, then change the settings.

The first is probably the most correct but I don't think there is a big difference.

Any removal of existing tests, or change of required tests, will cause existing PRs to break until a rebase to the latest codebase. The timing is probably does not change things much.