add downstream tests in upstream packages

[juliasloan25]

#1033 introduces a test/runtest.jl file that can be run from upstream packages to determine downstream compatibility. Now we need to use it from various upstream packages.

Packages to update

• ClimaAtmos update coupler downstream test ClimaAtmos.jl#3393
• ClimaLand update coupler downstream test ClimaLand.jl#875
• ClimaUtilities Update downstream job for Julia 1.11 and AMIP ClimaUtilities.jl#121
• ClimaDiagnostics Add ClimaCoupler and Julia 1.11 to downstream test ClimaDiagnostics.jl#91
• SurfaceFluxes add ClimaCoupler downstream test SurfaceFluxes.jl#179
• Thermodynamics add ClimaCoupler downstream experiment Thermodynamics.jl#231
• ClimaCore add ClimaCoupler downstream AMIP test ClimaCore.jl#2056
• RRTMGP add coupler AMIP downstream test; add Julia 1.11 to downstream tests RRTMGP.jl#558

[juliasloan25]

the downstream AMIP test has been added to all of the listed packages