WRF CAMtr_mixing_ratio files for CMIP7 scenarios

[jesusff]

@LluisFB comment moved from off-topic thread in WCRP-CORDEX/experiment-design#1

@jesusff, should we produce the CAMtr_mixing_ratio files for WRF from these scenarios? Although it is not clear to me with this new 'emissions-driven' rationale if there is still a unique GHG global concentration usefull for all GCMs or it has to be done for each GCM?

[jesusff]

For the emission-driven GCMs, we'll need to create specific CAMtr_mixing_ratio files for each GCM simulation. For the concentration-driven runs, we can have generic files for each scenario, as we did for the SSPs in https://github.com/SantanderMetGroup/wrf-ghg-files