Lodestar v1.7.0 Adds EIP-8045, Excludes Slashed Validators

Lodestar v1.7.0-alpha.8 spec upgrade adds EIP-8045, excluding slashed validators from proposing. Emits fast_confirmation SSE events, implements fast confirmation rule, and forces proposer reorgs of late or unavailable payloads. Adds gossip bid selection and proposer preferences. Bug fixes defer proposer duties v2 to gloas and handle post-gloas empty blocks.