[ty] Make Python-version subdiagnostics less verbose

[AlexWaygood]

Summary

@MichaReiser mentioned in astral-sh/ty#1582 (comment) that these subdiagnostics currently repeat some information from the primary diagnostic, which feels unnecessary. I agree.

Before:

Before

After

Test Plan

Snapshots updated

[astral-sh-bot]

Diagnostic diff on typing conformance tests

No changes detected when running ty on typing conformance tests ✅

[astral-sh-bot]

mypy_primer results

Changes were detected when running on open source projects

beartype (https://github.com/beartype/beartype)
+ beartype/claw/_package/clawpkgtrie.py:66:29: warning[unsupported-base] Unsupported class base with type `<class 'dict[str, PackagesTrieBlacklist]'> | <class 'dict[str, Divergent]'>`
+ beartype/claw/_package/clawpkgtrie.py:247:29: warning[unsupported-base] Unsupported class base with type `<class 'dict[str, PackagesTrieWhitelist]'> | <class 'dict[str, Divergent]'>`
- Found 492 diagnostics
+ Found 494 diagnostics

scikit-build-core (https://github.com/scikit-build/scikit-build-core)
- src/scikit_build_core/build/_pathutil.py:25:38: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `str | PathLike[str]`, found `DirEntry[Path]`
- src/scikit_build_core/build/_pathutil.py:27:24: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `str | PathLike[str]`, found `DirEntry[Path]`
- src/scikit_build_core/build/wheel.py:98:20: error[no-matching-overload] No overload of bound method `__init__` matches arguments
- Found 41 diagnostics
+ Found 38 diagnostics

No memory usage changes detected ✅

[MichaReiser]

Thank you

[codspeed-hq]

CodSpeed Performance Report

Merging #21849 will degrade performances by 4.31%

_{Comparing alex/py-version-verbosity (b14777c) with main (385dd27)}

Summary

❌ 1 regression
✅ 21 untouched
⏩ 30 skipped¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Mode	Benchmark	BASE	HEAD	Change
❌	WallTime	large[pydantic]	197.6 s	206.5 s	-4.31%

Footnotes

1. 30 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. ↩