Update dependency ruff to v0.16.4

[renovate]

This PR contains the following updates:

Package	Type	Update	Change	Pending
ruff	tools	patch	0.16.3 → 0.16.4	0.16.6 (+1)

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Release Notes

astral-sh/ruff (ruff)

v0.16.4

Compare Source

Released on 2026-08-20.

Preview features

• [flake8-use-pathlib] Add autofix for PTH116 (#​26460)
• [refurb] Restrict delete-full-slice to lists (FURB131) (#​27711)
• [refurb] Skip FURB101 and FURB103 when the open argument is a file descriptor (#​27643)

Bug fixes

• Fix InvalidInstruction on Windows CPUs that do not support POPCNT (#​27803)
• [pyflakes] Emit semantic syntax errors in string type definitions as F722 (#​27835)
• [pylint] Allow os._exit imports in import-private-name (PLC2701) (#​27738)

Rule changes

• [syntax-errors] Align mixed t-string/bytes error message with CPython 3.14 (#​27766)
• [ruff] Add ctypes.LittleEndianStructure and related types to existing exception (RUF012) (#​27753)
• [syntax-errors] Detect duplicate keyword arguments (#​17804)
• [syntax-errors] Detect parameters declared nonlocal (#​27628)

Server

• Offer display-only fixes and mark safe fixes preferred (#​27807)
• Support pull diagnostics for notebook cells (#​27779)

Documentation

• Add default indicator to rules table (#​27724)
• Fix broken link to Python docs (#​27757)

Other changes

• Fix s390x stacker assembly in release builds (#​27776)
• Guarantee minimum stack size when parsing a module, standalone expression, and suites (#​25464)
• Reduce configuration deserialization code size (#​27924)
• Check packed AST index bounds (#​27849)

Contributors

• @​AbhinavMir
• @​eduardorittner
• @​royb3
• @​MichaReiser
• @​carljm
• @​rosstitmarsh
• @​ntBre
• @​zaniebot
• @​ewdurbin
• @​woodruffw
• @​Sacrimento
• @​lakshayxi
• @​WhiteFox0-0
• @​baltasarblanco

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