spec: https://notes.ethereum.org/@ethpandaops/pectra-devnet-6 - [x] [Add SSZ support to builder API](https://github.com/ethereum/builder-specs/pull/104) - [x] [Add Electra blob sidecars type to support max blobs from EIP-7691](https://github.com/ethereum/beacon-APIs/pull/488) PRs: - https://github.com/sigp/lighthouse/pull/6859 - https://github.com/sigp/lighthouse/pull/6871 - https://github.com/sigp/lighthouse/pull/6867 - https://github.com/sigp/lighthouse/pull/6832 - https://github.com/sigp/lighthouse/pull/6819
