chore: Enable ty unused-ignore-comment rule

Now that ty supports detecting unused suppression comments (upstream
issues astral-sh/ty#278 and astral-sh/ty#1501 are closed), enable the
rule project-wide so obsolete `# ty: ignore[...]` comments are caught
automatically. Verified all current suppressions are still required.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: vdusek

pyproject.toml

@@ -186,6 +186,9 @@ python-version = "3.11"
 include = ["src", "tests", "scripts", "docs", "website"]
 exclude = ["website/versioned_docs"]
 
+[tool.ty.rules]
+unused-ignore-comment = "error"
+
 [[tool.ty.overrides]]
 include = ["docs/**/*.py", "website/**/*.py"]
 [tool.ty.overrides.rules]