[3.14] pythongh-133157: remove usage of _Py_NO_SANITIZE_UNDEFINED in Parser/pegen.c (pythonGH-134048) (python#135320)

pythongh-133157: remove usage of `_Py_NO_SANITIZE_UNDEFINED` in `Parser/pegen.c` (pythonGH-134048)
(cherry picked from commit 754e7c9)

Co-authored-by: Bénédikt Tran <[email protected]>

Author: miss-islington