[ruff] Fix panic in unused # noqa removal with multi-byte space (RUF100)

[diceroll123]

Summary

Currently, this line assumes that the noqa comment begins with an octothorpe followed by a space. (# ) With anyone's random code, this of course is not always true.

When there's a multi-byte character after the leading octothorpe, such as \u0085, we try slicing from within the character, causing a panic.

To fix this, the logic has been changed to remove unused noqa directives and keep any trailing comments, or removing the whole comment if the comment is just the unused noqa

Fixes #10097.

Test Plan

cargo test

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[charliermarsh]

Thanks!