chore: prepare release 0.1.27

[pinodeca]

Summary

• bump package version to 0.1.27 in Cargo and Python metadata
• add the 0.1.27 changelog entry for the duroxide 0.1.30 dependency update

Validation

• cargo clippy --all-targets
• maturin develop --release
• pytest -v with PostgreSQL: 153 passed
• built duroxide-0.1.27 wheel
• isolated wheel smoke test passed

Notes

The repository clean-venv smoke wrapper could not run because this host lacks the OS python3.12-venv package. The equivalent smoke test passed against the unpacked wheel from outside the repository; CI remains the authoritative multi-platform package gate.