Update dependency black to v26

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
black (changelog)	^25.9.0 → ^26.0.0

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Release Notes

psf/black (black)

v26.1.0

Compare Source

Highlights

Introduces the 2026 stable style (#​4892), stabilizing the following changes:

• always_one_newline_after_import: Always force one blank line after import
  statements, except when the line after the import is a comment or an import statement
  (#​4489)
• fix_fmt_skip_in_one_liners: Fix # fmt: skip behavior on one-liner declarations,
  such as def foo(): return "mock" # fmt: skip, where previously the declaration would
  have been incorrectly collapsed (#​4800)
• fix_module_docstring_detection: Fix module docstrings being treated as normal
  strings if preceded by comments (#​4764)
• fix_type_expansion_split: Fix type expansions split in generic functions (#​4777)
• multiline_string_handling: Make expressions involving multiline strings more compact
  (#​1879)
• normalize_cr_newlines: Add \r style newlines to the potential newlines to
  normalize file newlines both from and to (#​4710)
• remove_parens_around_except_types: Remove parentheses around multiple exception
  types in except and except* without as (#​4720)
• remove_parens_from_assignment_lhs: Remove unnecessary parentheses from the left-hand
  side of assignments while preserving magic trailing commas and intentional multiline
  formatting (#​4865)
• standardize_type_comments: Format type comments which have zero or more spaces
  between # and type: or between type: and value to # type: (value) (#​4645)

The following change was not in any previous stable release:

• Regenerated the _width_table.py and added tests for the Khmer language (#​4253)

This release alo bumps pathspec to v1 and fixes inconsistencies with Git's
.gitignore logic (#​4958). Now, files will be ignored if a pattern matches them, even
if the parent directory is directly unignored. For example, Black would previously
format exclude/not_this/foo.py with this .gitignore:

exclude/
!exclude/not_this/

Now, exclude/not_this/foo.py will remain ignored. To ensure exclude/not_this/ and
all of it's children are included in formatting (and in Git), use this .gitignore:

*/exclude/*
!*/exclude/not_this/

This new behavior matches Git. The leading */ are only necessary if you wish to ignore
matching subdirectories (like the previous behavior did), and not just matching root
directories.

Output

• Explicitly shutdown the multiprocessing manager when run in diff mode too (#​4952)

Integrations

• Upgraded PyPI upload workflow to use Trusted Publishing (#​4611)

v25.12.0

Compare Source

Highlights

• Black no longer supports running with Python 3.9 (#​4842)

Stable style

• Fix bug where comments preceding # fmt: off/# fmt: on blocks were incorrectly
  removed, particularly affecting Jupytext's # %% [markdown] comments (#​4845)
• Fix crash when multiple # fmt: skip comments are used in a multi-part if-clause, on
  string literals, or on dictionary entries with long lines (#​4872)
• Fix possible crash when fmt: directives aren't on the top level (#​4856)

Preview style

• Fix fmt: skip skipping the line after instead of the line it's on (#​4855)
• Remove unnecessary parentheses from the left-hand side of assignments while preserving
  magic trailing commas and intentional multiline formatting (#​4865)
• Fix fix_fmt_skip_in_one_liners crashing on with statements (#​4853)
• Fix fix_fmt_skip_in_one_liners crashing on annotated parameters (#​4854)
• Fix new lines being added after imports with # fmt: skip on them (#​4894)

Packaging

• Releases now include arm64 Windows binaries and wheels (#​4814)

Integrations

• Add output-file input to GitHub Action psf/black to write formatter output to a
  file for artifact capture and log cleanliness (#​4824)

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Configuration

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---

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[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: poetry.lock

Updating dependencies
Resolving dependencies...


The current project's supported Python range (>=3.9,<4.0) is not compatible with some of the required packages Python requirement:
  - black requires Python >=3.10, so it will not be installable for Python >=3.9,<3.10

Because no versions of black match >=26.0.0,<26.1.0 || >26.1.0,<27.0.0
 and black (26.1.0) requires Python >=3.10, black is forbidden.
So, because guacapy depends on black (^26.0.0), version solving failed.

  * Check your dependencies Python requirement: The Python requirement can be specified via the `python` or `markers` properties

    For black, a possible solution would be to set the `python` property to ">=3.10,<4.0"

    https://python-poetry.org/docs/dependency-specification/#python-restricted-dependencies,
    https://python-poetry.org/docs/dependency-specification/#using-environment-markers