Fix partitioner option and update Dockerfile for architecture

[rfiorella]

Summary

• Updates E3SM and Amanzi submodule pointers to working Coweeta versions
• Refines Coweeta example build configuration and partitioning options
• Improves Docker workflow with architecture tagging
• Removes validation script (now maintained in watershed_workflow)

Key Changes

• Fixed misplaced partitioner option in ATS XML
• Enhanced Coweeta build script with better path handling and configuration
• Specified architecture tag in Dockerfile-run for consistent builds
• Improved build_example.sh path resolution for Docker environments
• Cleaned up validation script now that it's in watershed_workflow submodule