* also pack attestations where LMD vote is orphaned
When `attestation.data.beacon_block_root` gets orphaned, attestations
with a good `attestation.data.target.root` may still be valuable.
The LMD GHOST vote is not relevant for attestation rewards.
Switch to use the FFG vote (`attestation.data.target.root`) instead,
gossip validation ensures it is an ancestor of `beacon_block_root`.
* lint
12381d5f33