[3.12] gh-66819: More IDLE htest updates(2) (GH-112642) (#112643)

Examine and update spec -- callable pairs.
Revise run method.
(cherry picked from commit 3855b45874d5f8eb92a4957fb9de6fdce63eb760)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>