[seddonym]

Drop support for Python 3.10, which is now end-of-life.

While we're at it, add some docs for doing this, and a just modernize-python command to modernize any syntax we no longer need to support.

[Copilot]

🟡 Changes recommended

The modernization recipe fails under Ubuntu’s default sh due to unsupported brace expansion, and the interpreter-list guidance risks shadowing regular interpreters and omitting their wheels.

2 open issues

• Avoid Bash brace expansion in the POSIX-shell recipe · New
• Keep regular and free-threaded interpreter lists separate · New

What changed in this PR

Raises Grimp’s minimum supported Python version to 3.11 and adds tooling and contributor guidance for future Python-version changes.

Changes:

• Removes Python 3.10 from package metadata, test matrices, release builds, and dependency resolution.
• Updates typing annotations and imports.
• Adds a modernize-python recipe and documents how to add or drop Python support.

File	Description
uv.lock	Updates dependency resolution for Python 3.11+ and adds pyupgrade.
tests/​unit/​application/​graph/​test_manipulation.py	Imports NotRequired from standard-library typing.
tests/​adaptors/​filesystem.py	Simplifies a generator annotation.
src/​grimp/​application/​ports/​timing.py	Uses Self for the context-manager return type.
pyproject.toml	Raises the Python minimum and adds pyupgrade.
justfile	Drops Python 3.10 testing and adds modernization tooling.
CONTRIBUTING.rst	Documents Python-version support changes.
CHANGELOG.rst	Records removal of Python 3.10 support.
.github/​workflows/​release.yml	Removes Python 3.10 from wheel builds.
.github/​workflows/​main.yml	Removes Python 3.10 from the test matrix.

_{Review effort: Balanced}

[codspeed]

Merging this PR will not alter performance

✅ 26 untouched benchmarks
⏩ 23 skipped benchmarks¹

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_{Comparing drop-python-310-support (a8d1613) with main (39ea1a5)}

Footnotes

1. 23 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩