build(deps): bump pyflakes from 1.6.0 to 2.3.1

[dependabot-preview]

Bumps pyflakes from 1.6.0 to 2.3.1.

Changelog

Sourced from pyflakes's changelog.

2.3.1 (2021-03-24)

• Fix regression in 2.3.0: type annotations no longer redefine imports

2.3.0 (2021-03-14)

• Recognize tuple concatenation in __all__ export definitions
• Better support use of annotation-only assignments when using from __future__ import annotations
• Recognize special-case typing for Annotated
• Fix undefined name __qualname__ in class scope
• Recognize special-cased typing for TypeVar
• Errors for undefined exports in __all__ are shown in a deterministic order
• Fix false positives in certain typing constructs (TypeVar, NamedTuple, TypedDict, cast)

2.2.0 (2020-04-08)

• Include column information in error messages
• Fix @overload detection with other decorators and in non-global scopes
• Fix return-type annotation being a class member
• Fix assignment to _ in doctests with existing _ name
• Namespace attributes which are attached to ast nodes with _pyflakes_ to avoid conflicts with other libraries (notably bandit)
• Add check for f-strings without placeholders
• Add check for unused/extra/invalid 'string literal'.format(...)
• Add check for unused/extra/invalid 'string literal % ...
• Improve python shebang detection
• Allow type ignore to be followed by a code # type: ignore[attr-defined]
• Add support for assignment expressions (PEP 572)
• Support @overload detection from typing_extensions as well
• Fix @overload detection for async functions
• Allow continue inside finally in python 3.8+
• Fix handling of annotations in positional-only arguments
• Make pyflakes more resistant to future syntax additions
• Fix false positives in partially quoted type annotations
• Warn about is comparison to tuples
• Fix Checker usage with async function subtrees
• Add check for if of non-empty tuple
• Switch from optparse to argparse
• Fix false positives in partially quoted type annotations in unusual contexts
• Be more cautious when identifying Literal type expressions

2.1.1 (2019-02-28)

• Fix reported line number for type comment errors
• Fix typing.overload check to only check imported names

2.1.0 (2019-01-23)

• Allow intentional assignment to variables named _
• Recognize __module__ as a valid name in class scope
• pyflakes.checker.Checker supports checking of partial ast trees

... (truncated)

Commits

• 95fe313 Release 2.3.1
• 3de8e61 Annotations no longer redefine names (#619)
• 22eaa06 allow passing tox positional arguments to unittest (#624)
• 40e6dc2 Release 2.3.0 (#608)
• e3f2659 Fix: Named types incorrectly raising UndefinedName inside annotated subscript...
• 43541ee Fix annotation clobbering all (#606)
• 650efb9 deterministic ordering for errors in all (#604)
• d2ab3ec Fix quoted type annotations in typing.TypeVar contexts (#534)
• 0e4194b Test PyPy2/3 on GHA (#598)
• 632e346 Test on GitHub Actions (#596)
• Additional commits viewable in compare view

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