[3.12] gh-105623 Fix performance degradation in logging RotatingFileHandler (GH-105887) (GH-121116)

The check for whether the log file is a real file is expensive on NFS
filesystems.  This commit reorders the rollover condition checking to
not do the file type check if the expected file size is less than the
rotation threshold.

(cherry picked from commit e9b4ec614b66d11623b80471409c16a109f888d5)

Co-authored-by: Craig Robson <craig@zhatt.com>
Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>