Description

In #3157 we removed finalized payloads from the database in favour of reconstructing them from the execution layer. Our reconstruction depends on the correctness of the ethers library's transaction encoding, and it would be good to ensure this is correct in CI.

To do this we need to add some transactions to the execution blocks in our EE integration tests. This will involve creating and signing transactions, preferably of several different types (EIP-1559 and legacy), publishing them to the EE, ensuring they get included in payloads and that these payloads can be reconstructed.

Deeper testing could involve fuzzing, or live network testing (e.g. trying to reconstruct every block on Kiln)