Use nwm-ewts repository Python Package

[mxkpp]

The Error and Warning Trapping System has been refactored into a single repository that includes a Python package.
This update removes the previous package in this repository.

Additions

• import the ewts package

Removals

• The ngen Forcing repository nextgen_forcing_ewts package

Changes

• Update git workflow for unit tests to install from the nwm-ewts repository python package

Testing

1. Local testing with ngen and PW testing on DEV2 cluster

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• Placeholder code is flagged / future todos are captured in comments
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Target Environment support

• Linux