ruff: extended-ignore → ignore (jaraco/skeleton#105)

Applies Repo-Review suggestion:
	RF201: Avoid using deprecated config settings
	extend-ignore deprecated, use ignore instead (identical)

ruff.toml

@@ -1,5 +1,5 @@
 [lint]
-extend-ignore = [
+ignore = [
 	# https://docs.astral.sh/ruff/formatter/#conflicting-lint-rules
 	"W191",
 	"E111",