Try out DowngradeCI

[charleskawczynski]

A step towards https://github.com/CliMA/ProjectManagement/issues/34

xref: https://github.com/julia-actions/julia-downgrade-compat

[Sbozzolo]

I added a similar workflow in ClimaUtilities, ClimaDiagnostics, and ClimaAnalysis. It is a little bit laborious to find the lower bounds the first time (if you want to do this right). The fastest way I found to do this is by trying locally by setting = in the compats and fix one dependency at the time. All the Julia stdlib packages should be ignored, or the workflow will fail across different versions of Julia.