Improve Continuous Integration via Witness-generation only tests

[pgebheim]

• official Ethereum tests in the zk_evm CI (witness generation only): either hardcoded or random
• some concrete blocks (either L1 or John's chain) to test the decoder parsing logic + witness generation
• setting up an infra for regular testing and regression catch (we'd need to define the frequency, the types of run, the tests to be run)

[Nashtare]

I think some of those may be better suited for the zk_evm repo CI, as this is where PRs touching the logic are critical.

[pgebheim]

That's probably true -- I'll transfer this to the other repo.

[Nashtare]

This can probably wait until we merge the feat/cancun branch, or be targeted directly against this branch, given that this is going to happen soon and would break all hardcoded tests.

One thing that may be nice if running all tests takes too much time could be to have a CI job picking at random N tests from the Ethereum test suite (they can be preprocessed as done here), and persisting them upon failure until they're being cleared out for reproduceability, somewhat like how proptests work.

On current develop, blacklisting tests that are too expensive to run (either insane gas consumed or insame # ops), the remaining ~13k tests were taking ~2h to run on my M2 pro (for witness generation). Given that no parallelism was involved, we could reasonably have the CI check a few hundreds per run, if not more by using a self-hosted runner + adding multi-threading.

[temaniarpit27]

@Nashtare
I think this task can be covered with the following tasks: #726 #704 as I discussed with ben last time
Let me know your thoughts

[Nashtare]

Agreed, closing this one.