bpo-45118: Fix regrtest second summary for re-run tests (GH-28183) (GH-28214)

Fix regrtest second summary when using -w/--verbose2 command line
option: lists re-run tests in the second test summary.
(cherry picked from commit c4ea45d7d2c02674db2fdb96c7eee89324d2dc64)

Co-authored-by: Victor Stinner <vstinner@python.org>