Creating Deterministic Zip Files with Git Commit Timestamps

When packaging files into zip archives as part of a CI/CD pipeline, naive zip commands produce different hashes on every run due to changing file timestamps — even when file contents are unchanged. This causes tools like rsync to re-upload all archives unnecessarily. The solution is to normalize file timestamps before zipping by setting each file's timestamp to its last git commit time using `git ls-tree` and `touch`. This ensures deterministic archive hashes across machines and builds, so only genuinely changed archives are uploaded.