Update ruff to 0.15.4

[pyup-bot]

This PR updates ruff from 0.15.3 to 0.15.4.

Changelog

0.15.4

Released on 2026-02-26.

This is a follow-up release to 0.15.3 that resolves a panic when the new rule `PLR1712` was enabled with any rule that analyzes definitions, such as many of the `ANN` or `D` rules.

Bug fixes

- Fix panic on access to definitions after analyzing definitions ([23588](https://github.com/astral-sh/ruff/pull/23588))
- \[`pyflakes`\] Suppress false positive in `F821` for names used before `del` in stub files ([23550](https://github.com/astral-sh/ruff/pull/23550))

Documentation

- Clarify first-party import detection in Ruff ([23591](https://github.com/astral-sh/ruff/pull/23591))
- Fix incorrect `import-heading` example ([23568](https://github.com/astral-sh/ruff/pull/23568))

Contributors

- [stakeswky](https://github.com/stakeswky)
- [ntBre](https://github.com/ntBre)
- [thejcannon](https://github.com/thejcannon)
- [GeObts](https://github.com/GeObts)

Links

• PyPI: https://pypi.org/project/ruff
• Changelog: https://data.safetycli.com/changelogs/ruff/
• Homepage: https://docs.astral.sh/ruff