Remove test_consolidation.py since they are not valid test vectors

[hwwhww]

Apologized. Leftover of #3724.

Reported by @tersec:

https://github.com/ethereum/consensus-spec-tests/tree/v1.5.0-alpha.1/tests/minimal/electra/sanity/blocks/pyspec_tests/multiple_consolidations_above_churn~ has no pre-state
Also, and caveat, I've not verified this one as closely, but it happens before any actual block processing, so it'd have to be an SSZ reading issue if it is a Nimbus issue at all, the Electra minimal block sanity multiple_consolidations_below_churn, multiple_consolidations_equal_churn, and multiple_consolidations_equal_twice_churn all fail for Nimbus's test fixture on the verify first block, before being able to apply it, on (Nimbus's equivalent of)

It turns out that the original test script used set_eth1_withdrawal_credential_with_balance to manipulate the pre state in the for loop, so it can't be the valid test vectors.

@fradamt once suggested that it's OK to delete these tests. This PR removes these test cases.

[ralexstokes]

works for me, we can revisit proper testing over the coming months