Update ruff to 0.6.8

[pyup-bot]

This PR updates ruff from 0.6.7 to 0.6.8.

Changelog

0.6.8

Preview features

- Remove unnecessary parentheses around `match case` clauses ([13510](https://github.com/astral-sh/ruff/pull/13510))
- Parenthesize overlong `if` guards in `match..case` clauses ([13513](https://github.com/astral-sh/ruff/pull/13513))
- Detect basic wildcard imports in `ruff analyze graph` ([13486](https://github.com/astral-sh/ruff/pull/13486))
- \[`pylint`\] Implement `boolean-chained-comparison` (`R1716`) ([13435](https://github.com/astral-sh/ruff/pull/13435))

Rule changes

- \[`lake8-simplify`\] Detect `SIM910` when using variadic keyword arguments, i.e., `**kwargs` ([13503](https://github.com/astral-sh/ruff/pull/13503))
- \[`pyupgrade`\] Avoid false negatives with non-reference shadowed bindings of loop variables (`UP028`) ([13504](https://github.com/astral-sh/ruff/pull/13504))

Bug fixes

- Detect tuples bound to variadic positional arguments i.e. `*args` ([13512](https://github.com/astral-sh/ruff/pull/13512))
- Exit gracefully on broken pipe errors ([13485](https://github.com/astral-sh/ruff/pull/13485))
- Avoid panic when analyze graph hits broken pipe ([13484](https://github.com/astral-sh/ruff/pull/13484))

Performance

- Reuse `BTreeSets` in module resolver ([13440](https://github.com/astral-sh/ruff/pull/13440))
- Skip traversal for non-compound statements ([13441](https://github.com/astral-sh/ruff/pull/13441))

Links

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