CI failing on macos-latest

[kafitzgerald]

CI is now failing on macos-latest because it changed to using M1s that WRF-Python (and maybe other dependencies) doesn't support.

Here's the error:

  error    libmamba Could not solve for environment specs
      The following package could not be installed
      └─ wrf-python does not exist (perhaps a typo or a missing channel).
  critical libmamba Could not solve for environment specs

I think for the time being we should change back to the older macos runners, but it'd be good to prioritize addressing this in the dependencies we maintain or look for replacements.

I've logged support for Apple silicon as #604.

[kafitzgerald]

Addressed by #605.