Use EWTS repository Python package

[cmaynard-ngwpc]

Summary

Refactor to use the EWTS-based logging by centralizing logger initialization, standardizing log naming, and ensuring consistent usage across the codebase.

Additions

• Centralized logger initialization utility in utils.py for consistent logger configuration and reuse.
• Added prefixes for ngen logs by setting the new NGEN_LOG_FILE_PREFIX environment variable

Updates

• Migrated remaining logging to use EWTS across the codebase.
• Standardized log naming by prefixing ngen stdout/stderr logs with the job ID for better traceability
• Refactored logger setup to rely on the new shared utility.
• Added cache bust args to the Dockerfile

Removals

• Removed redundant logger initialization in favor of the centralized utility.