Schedule Capella for Gnosis chain (sigp#4433)

Closes sigp#4422
Implements gnosischain/configs#12

Schedule the Capella fork for Gnosis chain at epoch 648704, August 1st 2023 11:34:20 UTC.

Author: michaelsproul

consensus/types/src/chain_spec.rs

@@ -856,7 +856,7 @@ impl ChainSpec {
              * Capella hard fork params
              */
             capella_fork_version: [0x03, 0x00, 0x00, 0x64],
-            capella_fork_epoch: None,
+            capella_fork_epoch: Some(Epoch::new(648704)),
             max_validators_per_withdrawals_sweep: 8192,
 
             /*