[stanleys12]

Summary

Drops the safe_serialization option from the Hugging Face export.

Motivation

Transformers 5 doesn't accept safe_serialization in push_to_hub anymore and always saves safetensors. So every export fails with a TypeError.

Changes

• Stop passing safe_serialization in publish_model_to_hugging_face
• Remove the toggle from the push dialog and the config default
• Remove the -s flag from publish_to_hugging_face.py and update the docs
• Add a unit test with a backbone whose push_to_hub lacks the kwarg

Testing

• With hugging_face_utils.py reverted to main, .venv/bin/python -m pytest tests/app_utils/test_hugging_face_utils.py fails with a TypeError on safe_serialization.
• With the fix, the same command passes (1 passed).
• ruff format --check, ruff check and mypy pass on the touched Python files.
• I didn't run the full make test or make style locally (I'm on macOS and the project only resolves on Linux x86_64), so I'm counting on CI for those.

AI assistance

I used an AI coding assistant (Claude Code) to draft this. I checked it by running the tests and linters listed above.

Checklist

• The title gives a clear summary.
• The related issue is linked below.
• The PR is not a work in progress.
• make test passes (only the targeted test file was run locally, CI will run the rest).
• make style passes (ran ruff and mypy on touched files, CI will run the full check).

Related issues

Fixes #1120