Description
We should get the storage root of the L1 to L1 message passer and set that as the withdrawals hash, like in based-op-geth:
https://github.com/gattaca-com/based-op-geth/blob/b92460b0d0c5eb5588baa966edb8cda277df5eba/beacon/engine/types.go#L444-L453
Currently, this won't work without BundleState, which we currently do not track but should. BundleState can only be read from a State DB (so not a cache). Will be a bit tricky to do.