`line_to_row` is a test function that converts `syslog` audit log to
the format of `table` audit log so tests can use the same checks
for both types of audit. Because `syslog` audit doesn't have `date`
information, the field was filled with the current date. This behavior
broke the tests running at 23:59:59 because `line_to_row` returned
different results on different days.
Fixes: scylladb/scylladb#25509
Closes scylladb/scylladb#26101
(cherry picked from commit 15e71ee083)
Closes scylladb/scylladb#26191