Pin pyFV3 to NDSL version 2026.01.00

[romanc]

Description

This PR pins pyFV3 to NDSL version 2026.01.00 (as discussed in the last NASA/NOAA NDSL sync) and updates code to remove any deprecation warnings.

How Has This Been Tested?

All good as long as CI is still green.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas: N/A
• I have made corresponding changes to the documentation: N/A
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included: N/A
• Targeted model if this changed was triggered by a model need/shortcoming: N/A

[romanc]

Ah apparently, we need to update pace first such that the CI hook of pace is happy with the changes here (pace still fetches the last version of NDSL).

[twicki]

Looks good, let's go!