`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