CDSM2 is no longer compatible with the latest build of CMOR

[mauzey1]

The last update to cmor-feedstock pinned libnetcdf 4.9.1 for CMOR. This has made the latest conda-forge build of CMOR 3.7.1 no longer compatible with CDMS2, which requires libnetcdf 4.8.1. This change also affects the nightly build as it pulls its build configuration from cmor-feedstock. Nightly builds of CMOR cannot be installed in the same conda environment as CDMS2 even if you pin the version of libnetcdf to 4.8.1.

Due to CDMS2 approaching End-of-Life by the end of 2023, I think this should be the point where we discontinue support of CDMS2. We can keep the code and tests that use CDMS2 in the repo for those who wish to still use it in source installs, but we should end our support of it in our builds.

[durack1]

Thanks @mauzey1 i think your suggestion is sad, but a reality.

Let's touch base next week to go through any remaining issues that I've been holding up for review, and push out a new release once these changes are made