Build oasis3-mct from master branch

[dougiesquire]

This PR is to create a prerelease of ACCESS-ESM1.6 using oasis3-mct built from the master branch (rather than the access-esm1.5 branch)

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🚀 The latest prerelease access-esm1p6/pr123-2 at 14421f1 is here: #123 (comment) 🚀

[github-actions]

🚀 Attempted to deploy access-esm1p6 Prerelease pr123-1 with commit 5e375d7

🖥️ Gadi Deployment ✔️

Usage Instructions

access-esm1.6, defined in ./spack.yaml, will be deployed to Gadi as:

• 2025.07.000 as a Release (when merged).
• pr123-1 as a Prerelease (during this PR).

This Prerelease is accessible on Gadi using:

module use /g/data/vk83/prerelease/modules
module load access-esm1p6/pr123-1

When using the above modules, the binaries shall be on your $PATH.

For advanced users, this Prerelease is also accessible on Gadi via /g/data/vk83/prerelease/apps/spack/0.22/spack in the access-esm1p6-pr123-1 environment.
Due to inode-saving measures, one will have to manually untar the environment metadata before environment activation with tar -xf .spack-env .spack-env.tar. It will require one to have write privileges.

Configuration Information

This Prerelease is deployed using:

• access-nri/spack on branch 0.22
• access-nri/spack-packages version 2025.08.000
• access-nri/spack-config version 2025.08.000

If the above was not what was expected, commit changes to config/versions.json in this PR.

[github-actions]

🚀 Attempted to deploy access-esm1p6 Prerelease pr123-2 with commit 14421f1

🖥️ Gadi Deployment ✔️

Usage Instructions

access-esm1.6, defined in ./spack.yaml, will be deployed to Gadi as:

• 2025.07.000 as a Release (when merged).
• pr123-2 as a Prerelease (during this PR).

This Prerelease is accessible on Gadi using:

module use /g/data/vk83/prerelease/modules
module load access-esm1p6/pr123-2

When using the above modules, the binaries shall be on your $PATH.

For advanced users, this Prerelease is also accessible on Gadi via /g/data/vk83/prerelease/apps/spack/0.22/spack in the access-esm1p6-pr123-2 environment.
Due to inode-saving measures, one will have to manually untar the environment metadata before environment activation with tar -xf .spack-env .spack-env.tar. It will require one to have write privileges.

Configuration Information

This Prerelease is deployed using:

• access-nri/spack on branch 0.22
• access-nri/spack-packages version 59bf398c2f482a47cd28c641589dfcfa7ae84cca
• access-nri/spack-config version 2025.08.000

If the above was not what was expected, commit changes to config/versions.json in this PR.