feat(make): automaticaly retrieve sha digest in newly created test modules

[raxhvl]

This would save a test implementer retrieving the value manually. Let's see if this feature #1537 proves to be useful before we add this.

For now we can populate these expected global variables with dummy values to make allow fill to run on these tests. I don't think it's worth trying to retrieve the required hash from ethereum/EIPs from Github in make test as I think we should remove this feature from fill sooner rather than later. It's not maintained or actively used.

Originally posted by @danceratopz in https://github.com/ethereum/execution-spec-tests/issues/950#issuecomment-2488285151