[3.12] gh-90535: Fix support of interval>1 in logging.TimedRotatingFileHandler (GH-116220) (GH-116892)

Fix support of interval values > 1 in logging.TimedRotatingFileHandler
for when='MIDNIGHT' and when='Wx'.
(cherry picked from commit 269051d20e65eda30734cbbbdb07d21df61978d6)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>