Bump black from 25.12.0 to 26.3.1

[dependabot]

Bumps black from 25.12.0 to 26.3.1.

Release notes

Sourced from black's releases.

26.3.1

Stable style

• Prevent Jupyter notebook magic masking collisions from corrupting cells by using exact-length placeholders for short magics and aborting if a placeholder can no longer be unmasked safely (#5038)

Configuration

• Always hash cache filename components derived from --python-cell-magics so custom magic names cannot affect cache paths (#5038)

Blackd

• Disable browser-originated requests by default, add configurable origin allowlisting and request body limits, and bound executor submissions to improve backpressure (#5039)

26.3.0

Stable style

• Don't double-decode input, causing non-UTF-8 files to be corrupted (#4964)
• Fix crash on standalone comment in lambda default arguments (#4993)
• Preserve parentheses when # type: ignore comments would be merged with other comments on the same line, preventing AST equivalence failures (#4888)

Preview style

• Fix bug where if guards in case blocks were incorrectly split when the pattern had a trailing comma (#4884)
• Fix string_processing crashing on unassigned long string literals with trailing commas (one-item tuples) (#4929)
• Simplify implementation of the power operator "hugging" logic (#4918)

Packaging

• Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments (#4930)

Performance

• Introduce winloop for windows as an alternative to uvloop (#4996)
• Remove deprecated function uvloop.install() in favor of uvloop.new_event_loop() (#4996)
• Rename maybe_install_uvloop function to maybe_use_uvloop to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop (#4996)

Output

... (truncated)

Changelog

Sourced from black's changelog.

Version 26.3.1

Stable style

• Prevent Jupyter notebook magic masking collisions from corrupting cells by using exact-length placeholders for short magics and aborting if a placeholder can no longer be unmasked safely (#5038)

Configuration

• Always hash cache filename components derived from --python-cell-magics so custom magic names cannot affect cache paths (#5038)

Blackd

• Disable browser-originated requests by default, add configurable origin allowlisting and request body limits, and bound executor submissions to improve backpressure (#5039)

Version 26.3.0

Stable style

• Don't double-decode input, causing non-UTF-8 files to be corrupted (#4964)
• Fix crash on standalone comment in lambda default arguments (#4993)
• Preserve parentheses when # type: ignore comments would be merged with other comments on the same line, preventing AST equivalence failures (#4888)

Preview style

• Fix bug where if guards in case blocks were incorrectly split when the pattern had a trailing comma (#4884)
• Fix string_processing crashing on unassigned long string literals with trailing commas (one-item tuples) (#4929)
• Simplify implementation of the power operator "hugging" logic (#4918)

Packaging

• Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments (#4930)

Performance

• Introduce winloop for windows as an alternative to uvloop (#4996)
• Remove deprecated function uvloop.install() in favor of uvloop.new_event_loop() (#4996)
• Rename maybe_install_uvloop function to maybe_use_uvloop to simplify loop installation and creation of either a uvloop/winloop eventloop or default eventloop (#4996)

... (truncated)

Commits

• c6755bb Prepare release 26.3.1 (#5046)
• 69973fd Harden blackd browser-facing request handling (#5039)
• 4937fe6 Fix some shenanigans with the cache file and IPython (#5038)
• 2e641d1 docs: remove outdated Black Playground references (#5044)
• c014b22 Remove unused internal code (#5041)
• 0dae20b Add new changelog (#5036)
• c5c1cbd Minor release patches (#5035)
• 7e5a828 docs: clarify relationship between Black style and PEP 8 (#5025)
• 69705de docs: add clearer pyproject configuration guidance (#5026)
• 35ea679 Prepare release 26.3.0 (#5032)
• Additional commits viewable in compare view

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[Copilot]

Pull request overview

This PR updates the repository’s Python dev dependency on black to version 26.3.1, keeping the development tooling (formatter) current and aligning the lockfile with the updated constraint.

Changes:

• Bump black in pyproject.toml dev dependency group from >=25.1.0,<26 to >=26.3.1,<27.
• Update uv.lock to reflect black==26.3.1 (artifacts + dev dependency metadata).

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
uv.lock	Updates locked black version/artifacts and the dev dependency constraint.
pyproject.toml	Updates the dev dependency version range for black.

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[jsjiang]

Changes look good and passed unit and built tests.