`fre.cmor`: adjust environment requirements and enable `cmor>3.11` compatibility

[ilaflott]

from my work in PR #539 , it appears the environment doesn't want to resolve to a solution using anything other than cmor=3.11.*. so something in the env is likely keeping any greater version from being pulled, and it may need to be adjusted to permit the latest and greatest CMOR 3.13.0 to be tested within fre-cli