Migrate package metadata from setup.py to pyproject.toml (PEP 621)

[sl0thentr0py]

Background

The package metadata still lives in setup.py (name, version, dependencies, extras, entry points, classifiers, etc.). pyproject.toml currently only carries tool configuration (coverage, pytest, mypy, ruff).

With the tox/uv migration landing (see #6325, #6327, #6367, and the rest of the chore/migrate-to-tox-uv work), the distribution itself is the last piece still using legacy setuptools configuration. Moving to PEP 621 [project] metadata would:

• Make the project introspectable by modern tooling (uv sync, uv add, pip install . without executing arbitrary Python, build frontends, dependency scanners, SBOM tools).
• Eliminate the setup.py execution step during builds.
• Align with the direction setuptools itself recommends.

Scope

Port everything currently in setup.py into pyproject.toml:

• [build-system] table (setuptools backend)
• [project] table: name, version, description, readme, requires-python, license, authors, urls, classifiers
• [project] dependencies ← install_requires
• [project.optional-dependencies] ← extras_require (all ~40 extras — names must match exactly; they're public API)
• [project.entry-points.\"opentelemetry_propagator\"] ← entry_points
• [tool.setuptools] zip-safe = false
• [tool.setuptools.package-data] for py.typed (PEP 561)
• [tool.setuptools.packages.find] with tests* excluded
• Verify MANIFEST.in still behaves correctly (or fold into include-package-data)
• Update release tooling (.craft.yml, version-bump scripts) to read/write the version in pyproject.toml instead of setup.py
• Remove setup.py once the above is verified

Verification

• python -m build produces an sdist + wheel byte-identical in contents (modulo metadata format) to the current release
• pip install sentry-sdk[flask], [django], [opentelemetry], etc. resolve identically
• py.typed is shipped in the wheel
• tests/ is not shipped in the wheel
• OTel propagator entry point is discoverable post-install
• Release pipeline dry-run succeeds

Risks

• Public-facing extras names — a typo silently breaks pip install sentry-sdk[name].
• Version bump automation — release tooling likely greps setup.py.
• python_requires=\">=3.6\" in current setup.py looks stale vs. the rest of the repo; worth confirming the intended floor before carrying it forward.

Related

• Tox/uv migration: test-asyncio: Migrate to uv and pyproject.toml #6325, test-asyncpg: Migrate to uv and pyproject.toml #6327, test-python312: Migrate to uv and pyproject.toml #6367, et al.
• Remove the universal bdist_wheel option in setup.py #6121 (removed bdist_wheel universal option)
• setup.py classifier produces inconsistent license information with piplicenses #5932 (license classifier inconsistency — pyproject migration is a chance to fix cleanly via license field)

[linear-code]

PY-2499