Add payload attestation validator duty (#9178)

Co-Authored-By: Eitan Seri-Levi <eserilev@ucsc.edu>

Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>

validator_client/validator_services/src/lib.rs

@@ -3,6 +3,7 @@ pub mod block_service;
 pub mod duties_service;
 pub mod latency_service;
 pub mod notifier_service;
+pub mod payload_attestation_service;
 pub mod preparation_service;
 pub mod sync;
 pub mod sync_committee_service;