pip(deps-dev): bump pyflakes from 3.4.0 to 4.0.0

[dependabot]

Bumps pyflakes from 3.4.0 to 4.0.0.

Changelog

Sourced from pyflakes's changelog.

4.0.0 (2026-09-22)

• Add support for python 3.15
• Drop support for EOL python 3.9
• Add new errors for lazy imports:
  • lazy import is eagerly used at module scope
  • lazy from ... import * is invalid syntax
  • lazy from __future__ import ... is invalid syntax
  • lazy import must be at module scope
• Improve typing specialization:
  • Handle cast(...) with named arguments
  • Fix duplicate errors in first argument of cast(...)
  • Handle TypeVar(... default='...')
  • Fix missing error for first argument of TypeVar(...) call
  • Update handling of NamedTuple(...) for python 3.15 changes
  • Update handling of TypedDict(...) for python 3.13 changes
  • Add handling of assert_type(...)
  • Add handling of NewType(...)
  • Add handling of TypeVarTuple(...)
  • Add handling of ParamSpec(...)
• Fix assignment expressions in dictionary literals
• Remove file_tokens parameter to Checker. Unused since 3.0.0
• Fix false-negative for deleting special variables such as del __tracebackhide__
• Add support for python3t shebangs
• Remove support for obsolete python3m and pythonu shebangs

Commits

• bda5e1d Release 4.0.0
• f6e565c remove redundant tests coverage check (#901)
• dbf9fcc enforce 100% test coverage (#900)
• c9619fc add test to ensure iterSourceCode does not process dead links (#899)
• a6e8a11 detect python3t and remove detection for python3m and pythonu (#897)
• fa7a02c add test for check(...) of non-string (#898)
• 2a8910c add test for submodule import redefining a name (#896)
• 5ef97ef improve coverage for all handling (#895)
• 66f1758 add test for call of attribute of undefined name (#894)
• dae13ed rework and test custom builtins (#893)
• Additional commits viewable in compare view