Skip assertion in audit log tests if results beat the baseline

[graphcareful]

From the most recent run of the audit log scale tests:

Traceback (most recent call last):
  File "/home/ubuntu/redpanda/tests/rptest/services/cluster.py", line 82, in wrapped
    r = f(self, *args, **kwargs)
  File "/home/ubuntu/redpanda/tests/rptest/scale_tests/audit_log_test.py", line 413, in test_audit_log
    assert pct_difference(audit_disabled_results.p90,
AssertionError

The test ended up failing because the results beat the baseline by greater then the hardcoded 10% threshold:

[INFO  - 2023-12-20 13:02:43,395 - audit_log_test - test_audit_log - lineno:402]: audit_disabled_results: {'time_elapsed': 163.91215109825134, 'total_produced': 837362, 'total_consumed': 837330, 'p50': 15477.83203125, 'p90': 134794.0625, 'p99': 839466.16796875}
[INFO  - 2023-12-20 13:02:43,395 - audit_log_test - test_audit_log - lineno:404]: audit_enabled_results: {'time_elapsed': 178.89132976531982, 'total_produced': 913621, 'total_consumed': 913596, 'p50': 16713.26171875, 'p90': 112903.02734375, 'p99': 730726.29296875}

The difference between p90 results is 17% however the enabled run was better !

This patch changes the logic to only perform the assertion in the case the run didn't beat the baseline run. Also removes the ok_to_fail tag

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.3.x
• v23.2.x
• v23.1.x

Release Notes

• none

[oleiman]

lgtm!

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/43242#018c8da6-1f4c-4993-9ccf-965fe6db5d66

[vbotbuildovich]

/backport v23.3.x