Rearrange UM_v7 branches to allow further ACCESS-ESM1.5 and ACCESS-ESM1.6 development?

I propose that we create an access-esm1.5 branch of the UM_v7 repository, so that the um7 Spack package can use version access-esm1.5 and branch access-esm1.5 as per the other access-esm1.5 related packages.

This is partly because there is already an ESM1.6 branch, (which should eventually be renamed access-esm1.6 for the sake of consistency).

The ACCESS-ESM1.6 development of UM_v7 should then be able to merge to the main branch until access-esm1.6 is ready to release.

What are your thoughts?

It seems that this post is a good place for me to add this. I have requested access to this repo, directly from Aidan.

Assuming ESM1.6 is a branch based on ESM1.5, can we start development on this branch (By branching off it of course and submitting PRs to merge back onto it). We are testing ESM1.5+CABLE3 ATM. The code base has existed for quite some time, and has undergone some basic testing. @RachelLaw is conducting some more thorough testing ATM. No doubt there will be developments to follow, but we can begin submitting this base version immediately. There are ESM1.6 changes on the ocean side(including WOMBAT), but Pearse wants to sort out the generic tracers issue before including this ESM1.6 change.

The CABLE3 version in the ESM1.5+CABLE3 needs updating, but this is something which would be better on top of the (for now) partial ESM1.6 development branch that we have. There are some slight changes from Tammas that need to go in as well.

In ESM1.5+CABLE3, CABLE is no longer scattered throughout UM7.3::src/atmosphere/boundary_layer/. It is a single directory, UM7.3::src/atmosphere/CABLE. Where CABLE/ is very close to CABLE in the git repo. Ideally the CABLE in ESM1.5+CABLE3, or ESM1.6 should point to git::CABLE-LSM/CABLE, so there can be no confusion and we ALL point to the same CABLE.