docs: Correct collections-named-tuple example to use PascalCase assignment

[gopoto]

Summary

The documentation for collections-named-tuple (PYI024) was using a lowercase variable in its example:

from collections import namedtuple

person = namedtuple("Person", ["name", "age"])

while the recommended replacement used class Person – implying a name change that's not equivalent. This patch updates the docstring to use a more canonical example:

from collections import namedtuple

Person = namedtuple("Person", ["name", "age"])

so that the “Use instead:” block aligns with the original name and doesn't suggest a breaking rename. No functional code changes were required.

Test Plan

Only documentation comments were updated; the existing flake8_pyi tests still pass (cargo test -p ruff_linter). Running the full workspace tests yields a failure in an unrelated snapshot when run as root, but in a typical developer environment the existing tests and snapshots remain unaffected. All style and lint checks pass (cargo clippy, cargo fmt, etc.).

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This PR was generated by an AI system in collaboration with maintainers: @carljm, @ntBre

Fixes #16492

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.