fix(tests): size the merged placeholder pubkeys from PUBLIC_KEY_SIZE

The latest merge from main brought in two more test helpers (#554, #556)
that build validators with hardcoded 52-byte pubkeys, which do not compile
on this branch: tracking leanVM main shrinks XMSS pubkeys to 32 bytes.
Reference the constant so the size follows the type, same as 8f6a6b6 did
for the helpers the previous merge carried over.

Author: MegaRedHand

bin/ethlambda/src/main.rs

@@ -1028,7 +1028,7 @@ validators:
         seed_db(backend.clone(), &seeded_genesis);
 
         let mut other_genesis = test_genesis(genesis_time);
-        other_genesis.genesis_validators[0].attestation_pubkey = [9u8; 52];
+        other_genesis.genesis_validators[0].attestation_pubkey = [9u8; PUBLIC_KEY_SIZE];
         let Err(err) = fetch_initial_state(&[], &other_genesis, backend).await else {
             panic!("a foreign validator set must not be silently re-anchored");
         };

crates/storage/src/store.rs

@@ -1732,13 +1732,14 @@ mod tests {
     use super::*;
     use crate::backend::InMemoryBackend;
     use ethlambda_types::genesis::{GenesisMismatch, GenesisValidatorEntry};
+    use ethlambda_types::state::PUBLIC_KEY_SIZE;
 
     /// Validator at `index` whose two pubkeys are filled with `seed`, so
     /// changing the seed changes the registry without changing its size.
     fn validator(index: u64, seed: u8) -> Validator {
         Validator {
-            attestation_pubkey: [seed; 52],
-            proposal_pubkey: [seed.wrapping_add(1); 52],
+            attestation_pubkey: [seed; PUBLIC_KEY_SIZE],
+            proposal_pubkey: [seed.wrapping_add(1); PUBLIC_KEY_SIZE],
             index,
         }
     }