* Fix blob syncing for Electra
`BlobSidecar` requests on libp2p have a context prefix based on:
> The `<context-bytes>` field is calculated as context =
> `compute_fork_digest(fork_version, genesis_validators_root)`
We currently only process blobs if that indicates Deneb, meaning that
on Electra we incorrectly report `InvalidContextBytes` and refuse to
process the blob response data.
Fix this, and also ensure that the code no longer needs maintenance
with every fork unrelated to blobs.
* fix
ae0a1488b5