The comment in `readExecutionTransaction` is not actually relevant when
the `rlp.decode` template is called from a non-generic function.
The function still cannot be simply inlined; `is_valid_versioned_hashes`
is itself generic and would require an `export eth_types_rlp` to work
properly (generic sandwich issue). The non-generic function wrapper
seems simpler and avoids injecting RLP into importing modules.
* check blob versioned hashes when no EL is connected
When no EL is conencted, we have to at the very least ensure that the
data in the beacon block is consistent with the execution payload.
We already do this for the block hash, but also have to do it for the
`blob_kzg_commitments`. To validate that they are linked with the
execution payload, we have to RLP decode all EIP-4844 blob transactions
and compare their blob versioned hashes with the hashed commitments.
* simplify loop in case where `blob_versioned_hashes` doesn't exist
* skip blob transaction parsing pre Deneb
Etan Kissling