[3.11] gh-116563: Update tutorial error example (GH-116569) (#116625)

There now may be multiple carets pointing at a token
rather than just a character.  Fix the sentence about
possible causes.
(cherry picked from commit 3e45030076bf2cfab41c4456c73fb212b7322c60)

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