Test suite adjustments.
Attempted fixed gnarly Python test suite timing issue with p4verify.log indicating:
sys:1: ResourceWarning: unclosed file <_io.TextIOWrapper name=5 encoding='ANSI_X3.4-1968'>
(Seeing this in my local Docker environment only; the official test suite gets
past this with no issues).
Add an explicit file close() call in the function that reads log contents, as the log
is rotate too quickly for it to close naturally.
Adjusted checkpoint number to try to fix journal sequence issue in test for
load_checkpoint.sh.