(MAINT) Rename build scripts

[michaeltlombardi]

PR Summary

This change:

• Renames build.ps1 to packaging.ps1 to reflect its continued use in packaging releases.
• Renames build.new.ps1 to build.ps1 as the default build script.
• Removes the build.comparison.ps1 script as it's no longer needed.
• Updates all references to build.new.ps1 in project configuration, CI automation, and maintainer documentation.

PR Context

This change renames the build scripts. Previously, we had both build.ps1 and build.new.ps1. It's been a few months since we transitioned to the new build script, which has been functional for our CI and local development.

For now, we're keeping the legacy script as packaging.ps1 until we confirm that the new build script is equally functional for packaging a release.