python 3.11 build about cmor

[mauzey1]

Python 3.11 builds were recently made for the stable 3.7.0 release. conda-forge/cmor-feedstock#53

The only problem is that cdms2 doesn't have a Python 3.11 build so it can't be supported in future CMOR builds unless a new cdms2 build is uploaded to conda-forge.

[mauzey1]

When the Python 3.11 builds were created for conda-forge, the Python 3.7 builds got removed. This is why our Python 3.7 nightly builds were failing. I think we should also remove Python 3.7 from our nightly builds.

I will apply all these changes and create a PR once cdms2 is ready on conda-forge.

[mauzey1]

Since cdtime will not be supporting Python 3.11, as mentioned in conda-forge/cdms2-feedstock#80 (comment), we should discontinue CDMS2 support in CMOR for Python 3.11 and onward. We might even consider dropping CDMS2 support entirely in future CMOR 3.x releases as CDAT will be ending support by the end of 2023.

Should we consider supporting xCDAT in future releases?