Add legacy cfgs for zppy v3.1.0

[forsyth2]

Summary

Objectives:

• Add legacy cfgs for zppy v3.1.0

Select one: This pull request is...

• a bug fix: increment the patch version
• a small improvement: increment the minor version
• a new feature: increment the minor version
• an incompatible (non-backwards compatible) API change: increment the major version

Small Change

• To merge, I will use "Squash and merge". That is, this change should be a single commit.
• Logic: I have visually inspected the entire pull request myself.
• Pre-commit checks: All the pre-commits checks have passed.

[forsyth2]

@chengzhuzhang To continue legacy testing, I've added cfgs that are meant to be "frozen" in time at zppy v3.1.0. (Right now, they're identical copies of the main set of cfgs).

I think it would be over-testing to continue testing the v3.0.0 legacy cfgs as well, so my plan is to keep the cfgs but remove them from the default list (i.e., commenting them out in tests/integration/utils.py). That way, they can still be tested if questions of backwards compatibility arise or during more rigorous testing periods, like E3SM Unified testing.

Let me know if you have any questions/comments, otherwise I think this should be fine to merge.

[chengzhuzhang]

You plan sounds good to me. Thanks!

[forsyth2]

Sounds good, thanks! I'll go ahead and merge then.

[forsyth2]

This (the second commit, 4465ca4) is a minor update just for completeness. It's only relevant when TEST_SPECIFICS["cfgs_to_run"] == [] and I usually only run a subset of cfgs.