Reject attestations to blocks prior to the split

[michaelsproul]

With manual finalization, we added checks to reject blocks that conflict with the split point, which are effectively finalized.

We didn't add any checks to reject similar attestations. This is leading to a lot of noisy cache miss logs and "failed promises" in the committee cache on Holesky.

Mar 06 03:47:03.153 DEBG Committee cache miss head_block_root: 0xe156a286e3a24c81a5afb2c4a47cbd1a75be4ea25f5670c08dc5837a053244d1, shuffling_id: Epoch(118047), service: beacon

Mar 06 03:47:14.357 WARN State cache missed backtrace: 0: store::hot_cold_store::HotColdDB<E,Hot,Cold>::get_advanced_hot_state 1: network::network_beacon_processor::gossip_methods::<impl network::network_beacon_processor::NetworkBeaconProcessor>::process_gossip_attestation_to_convert 2: core::ops::function::FnOnce::call_once{{vtable.shim}} 3: tokio::runtime::task::raw::poll 4: std::sys::backtrace::__rust_begin_short_backtrace 5: core::ops::function::FnOnce::call_once{{vtable.shim}} 6: std::sys::pal::unix::thread::Thread::new::thread_start 7: 8:

Mar 06 03:47:14.366 DEBG Invalid attestation from network type: "unaggregated", peer_id: 16Uiu2HAmLAWYx8PBL8CQRTQAGLLvRtdMK2B7b4exaPju2fkLt57h, block: 0xe156a286e3a24c81a5afb2c4a47cbd1a75be4ea25f5670c08dc5837a053244d1, reason: BeaconChainError(MissingBeaconState(0x08f94dfd6adc67d6cfee4c4a99ecb2f53042f9808c7697f785292a2a141ac706))

This doesn't seem to have much performance impact, as no states end up being actually loaded from disk, however it does obscure legitimate state cache and committee cache misses, which is not ideal.

[eserilev]

I can pick this one up