OM4_025 preprocessing scripts no longer work

[jkrasting]

The OM4_025 preprocessing scripts no longer work:
https://github.com/NOAA-GFDL/MOM6-examples/tree/dev/gfdl/ice_ocean_SIS2/OM4_025/preprocessing

The instructions are out-of-date and refer to an environment on the GFDL system that no longer exists (i.e. module load python, which pointed to version 2.7).

Updated instructions are needed to regenerate the tools and input files for OM4_025.