chore!: require Python 3.11 or newer

[hassiebp]

What does this PR do?

Python SDK v5 requires Python >=3.11 (3.10 reaches end of life in October 2026). This redoes the closed #1923 on prepare-v5-release:

• requires-python = ">=3.11,<4.0" and ruff target-version = "py311"
• CI unit matrix: 3.11 to 3.14 (3.10 dropped); AGENTS.md CI contract updated
• removes the pre-3.11 fallbacks: asyncio.create_task(context=...) in the async-generator wrapper of observe, the typing_extensions.NotRequired fallback, and the skipif(python<3.11) markers
• uv.lock regenerated with the CI-pinned uv 0.11.2; only the 3.10-only packages (backports-asyncio-runner, exceptiongroup, tomli) and markers drop out. The relative exclude-newer header is kept as it was, so later lock edits on this stack don't collide with it.

Stack: 1 of 10 in the v5 stack. Base: prepare-v5-release. Merge this first.

Type of change

• Bug fix
• New feature
• Breaking change
• Refactor
• Documentation update
• Tooling, CI, or repo maintenance

Verification

uv run --frozen ruff check .                       # All checks passed!
uv run --frozen mypy langfuse --no-error-summary   # clean
uvx uv@0.11.2 lock --check                         # Resolved 91 packages
uv run --frozen pytest -n auto tests/unit          # 713 passed, 2 skipped (Python 3.12)
uv run --frozen --python 3.11 pytest -n auto tests/unit  # 713 passed, 2 skipped (Python 3.11)

Checklist

• I self-reviewed the diff using code_review.md.
• I added or updated tests for behavior changes.
• I updated docs, examples, or .env.template if needed.
• I did not hand-edit generated files; if generated files changed, I used the upstream regeneration path.
• I did not commit secrets or credentials.

  

Confidence Score: 4/5

The PR should not merge until @observe preserves asynchronous tracing for asyncio-marker-bearing callables.

Summary

The PR raises the SDK’s minimum Python version to 3.11, updates CI and tooling targets, and removes older-version fallbacks and lockfile entries.

• The coroutine predicate change also alters @observe dispatch for asyncio-marker-bearing callables on Python 3.11.

_{Reviews (1) · Last reviewed commit: "chore!: require Python 3.11 or newer"}

[github-actions]

@claude review

[chatgpt-codex-connector]

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-06T14:33:53.923668Z	18a7f21	PR opened

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[claude]

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[chatgpt-codex-connector]

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Reviewed commit: 18a7f21cbe

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[claude]

LGTM, straightforward minimum-Python-version bump.

What was reviewed: the pyproject.toml/ruff/CI matrix/AGENTS.md version bumps for consistency (all now 3.11+), the removal of the _ASYNCIO_CREATE_TASK_SUPPORTS_CONTEXT fallback and typing_extensions.NotRequired fallback in favor of direct 3.11+ APIs, and the corresponding test cleanup (removed skipif markers and the now-dead fallback test). The asyncio.iscoroutinefunction to inspect.iscoroutinefunction swap in observe.py was already investigated by the bug hunter as a candidate and ruled out as a duplicate.

Extended reasoning...

The diff is a mechanical minimum-Python-version bump (3.10 to 3.11) touching pyproject.toml, CI config, AGENTS.md docs, uv.lock, and two source files (observe.py, types.py) plus matching test removals; no security-sensitive surface (auth, crypto, permissions) is touched. Every file change matches the PR description precisely with no discrepancies found on inspection. The one non-mechanical code change (iscoroutinefunction swap) was already examined by the automated bug-hunting system and ruled out as a duplicate, leaving no open findings or unaddressed objections in the timeline.