refactor: remove hardcoded fulu fork

Author: fbwoolf

consensus/types/src/chain_spec.rs

@@ -220,6 +220,7 @@ pub struct ChainSpec {
      */
     /// Whether zkVM mode is enabled via CLI flag --activate-zkvm.
     /// When true, the node will subscribe to execution proof gossip, verify proofs,
+    /// TODO(ethproofs): Changed to Electra fork epoch.
     /// and optionally generate proofs. zkVM activates at the Fulu fork.
     /// Unlike other forks, this is not a network-wide activation but a per-node opt-in.
     pub zkvm_enabled: bool,
@@ -495,12 +496,14 @@ impl ChainSpec {
         self.zkvm_enabled
     }
 
+    /// TODO(ethproofs): Changed to Electra fork epoch.
+    ///
     /// Returns the epoch at which zkVM activates.
     /// Currently uses Fulu fork epoch.
     /// Returns None if zkVM is disabled or Fulu is not scheduled.
     pub fn zkvm_fork_epoch(&self) -> Option<Epoch> {
         if self.zkvm_enabled {
-            self.fulu_fork_epoch
+            self.electra_fork_epoch
         } else {
             None
         }