[3.9] bpo-42214: Fix check for NOTEQUAL token in the PEG parser for the barry_as_flufl rule (GH-23048) (GH-23051)

(cherry picked from commit 06f8c3328dcd81c84d1ee2b3a57b5381dcb38482)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
6 files changed