Remove ethhash/clique dependent test cases

[jwasinger]

Initial step for #29109 - redoing the chain maker with the new simulated backend may not be straightforward: chain maker allows very granular control over various aspects of the block and adapting the simulated backend to support this functionality can result in a complicated interaction/interface if it is not done properly.

However, as a first step: many test cases exist as a relic from the pre-merge time, where Geth had to keep track of competing side-forks and the complexity that entails. Such leftover testcases should be removed from the codebase.