perf: skip dispatch pipeline when all proof targets already fetched (#22147)

Co-authored-by: Ubuntu <ubuntu@dev-yk.tail388b2e.ts.net>

crates/engine/tree/src/tree/payload_processor/multiproof.rs

@@ -771,6 +771,11 @@ impl MultiProofTask {
     fn on_prefetch_proof(&mut self, mut targets: VersionedMultiProofTargets) -> u64 {
         // Remove already fetched proof targets to avoid redundant work.
         targets.retain_difference(&self.fetched_proof_targets);
+
+        if targets.is_empty() {
+            return 0;
+        }
+
         extend_multiproof_targets(&mut self.fetched_proof_targets, &targets);
 
         // For Legacy multiproofs, make sure all target accounts have an `AddedRemovedKeySet` in the
@@ -889,6 +894,10 @@ impl MultiProofTask {
             state_updates += 1;
         }
 
+        if not_fetched_state_update.is_empty() {
+            return state_updates;
+        }
+
         // Clone+Arc MultiAddedRemovedKeys for sharing with the dispatched multiproof tasks
         let multi_added_removed_keys = Arc::new(MultiAddedRemovedKeys {
             account: self.multi_added_removed_keys.account.clone(),