Add vicen, vsnon to activate zap_small_areas

[NickSzapiro-NOAA]

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PR checklist

• Short (1 sentence) summary of your PR:
  Add vicen, vsnon to activate zap_small_areas
• Developer(s):
  Elizabeth Hunke, Denise Worthen
• Suggest PR reviewers from list in the column to the right.
• Please copy the PR test results link or provide a summary of testing completed below.
  ufs-weather-model test case reproducer for negative dvice abort
• How much do the PR code changes differ from the unmodified code?
  • bit for bit
  • different at roundoff level
  • more substantial . While differences in values are less than puny, resolves model abort elsewhere originating from ice volume but no area
• Does this PR create or have dependencies on CICE or any other models?
  • Yes
  • No
• Does this PR add any new test cases?
  • Yes
  • No
• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/.)
  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No
• Please document the changes in detail, including why the changes are made. This will become part of the PR commit log.

Floating point math (e.g., in ridge_shift) may lead to tiny vicen increments without area that are not currently zapped. This zaps them too (+ similar logic for tiny vsnon). Closes #535

[apcraig]

I ran a full test suite on derecho with 4 compilers and everything was bit-for-bit. This suggests that fixing this error either has no impact on the results in our test suite or the error was not triggered for any gridcells in any tests. I think it's great to get this fixed, and it's good that it's unlikely to have an impact on the solutions in many cases.

https://github.com/CICE-Consortium/Test-Results/wiki/cice_by_hash_forks#227862610a87c6595de7ed6ea7583be228ca320b

[eclare108213]

Glad to get this fixed! Thank you.

[DeniseWorthen]

Great to get this fix in. Hopefully it will resolve most (maybe all?) of the negdvice failures we've been struggling with.

[NickSzapiro-NOAA]

@apcraig May I ask if you'd like me to make a PR on CICE side to update Icepack hash?

[apcraig]

Hi @NickSzapiro-NOAA. On my list, I'll try to take care of it today. Thanks for checking in and offering!