[dv] Rip out old checking where needed in test suite

[GregAC]

This is a reduced version of https://github.com/lowRISC/ibex/issues/1567 for M2.5. For tests that are fragile and falsely triggering the old checks we should just remove those checks.

Triage regression failures and determine what should be removed to bring pass rates up to standard

estimate 8

[GregAC]

estimate range: 4 - 8