Removing ndsl.Namelist from Pace

[jjuyeonkim]

Description

• Removes ndsl.Namelist from Pace
• Cleans up direct dacite usage for PhysicsConfig creation, using PhysicsConfig.from_dict instead.

This follows from PySHiELD PR #68, PyFV3 PR #88 and NDSL PR #246. It is part of NDSL Issue # 64.

This is intended to be the last PR before finally removing ndsl.Namelist.

How Has This Been Tested?

• Existing unit tests and CI translate tests pass.

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
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included

[romanc]

This looks great! Thanks for the cleanup 🧹