[3.12] gh-117995: Don't raise DeprecationWarnings for indexed nameless params (GH-118001) (#118142)

Filter out '?NNN' placeholders when looking for named params.

(cherry picked from commit 550483b7e6c54b2a25d4db0c4ca41bd9c1132f93)

Co-authored-by: Erlend E. Aasland <erlend@python.org>
Co-authored-by: AN Long <aisk@users.noreply.github.com>