feat: modernize to uv + pyproject.toml (PEP 621/735) + python-semantic-release

[farhan]

Important

PR implemented with the assistance of Claude Code. Refined and validated before being submitted for code review.

Modernize `enmerkar-underscore`
Part of openedx/public-engineering#518

Summary

• Repo publishes to PyPI: https://pypi.org/project/enmerkar-underscore/
• Replace `setup.py`/`setup.cfg` with `pyproject.toml` (PEP 621 static metadata)
• Switch from pip-compile to `uv` with PEP 735 dependency groups; commit `uv.lock`
• Retain flake8 as on master (no ruff introduced)
• Update CI to use `astral-sh/setup-uv`; SHA-pin all actions
• Add `python-semantic-release` + `release.yml` (OIDC trusted publishing)
• Drop Python 3.11 support; set `requires-python = ">=3.12"`

Removed/Updated

Deleted files: `setup.py`, `setup.cfg`, `requirements/`, `publish_pypi.yml`

Removed Makefile targets: None

Updated Makefile targets:

Target	Change
`upgrade`	Replaced pip-compile invocations with `edx_lint write_uv_constraints` + `uv lock --upgrade`
`requirements`	New target: `uv sync --group dev` + `uv tool install tox --with tox-uv`
`lint`	Fixed stale path `django-babel-underscore` → `src tests` (pre-existing breakage; `django-babel-underscore` was the original source directory name)

Python 3.11 dropped

Python 3.11 reached end-of-life on 2025-11-30 and Open edX Sumac dropped it platform-wide. Removed from the tox envlist, CI matrix, and classifiers.

Versioning

[Dynamic] `setuptools-scm` with `dynamic = ["version"]` — master had a PyPI publish workflow; `python-semantic-release` controls the version string at release time via git tags.

Important Notes

• OIDC trusted publisher must be configured on PyPI before merging. The new `release.yml` uses PyPI's OIDC trusted publishing (no token). Configure at https://pypi.org/manage/project/enmerkar-underscore/settings/publishing/ with workflow name `release.yml`.
• `publish_pypi.yml` was deleted — it used `requirements/pip.txt` (deleted) and `setup.py` (deleted) which no longer exist. `release.yml` is the replacement.
• `enmerkar==0.7.1` uses `pkg_resources` (removed from setuptools>=71). Pinned `setuptools<71` in `[tool.edx_lint].uv_constraints` until `enmerkar` is upgraded to use `importlib.metadata`.
• `pytest-pep8` and `pytest-flakes` (from original `test.in`) are incompatible with pytest 8+ on Python 3.12. Added `-p no:pep8 -p no:flakes` to the tox test command. These packages are retained in the dependency group to match the original `test.in`.
• The `docs/conf.py` has `import django-babel-underscore` (invalid Python syntax, pre-existing). The docs tox env and `doc` dependency group were omitted as the docs build was non-functional on master.
• `commitlint.yml` already existed on master — conventional commit format is already enforced.

Testing Notes

This PR has not been manually tested against the repo's own features. Testing relied on CI checks and local agent tooling (`make requirements`, `make test`, `python -m build`). Repo-owner is encouraged to run the repo's feature tests before merging.

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🤖 Generated with Claude Code