Set Swell Mainnet Holocene hardfork time (#1082)

Author: atenalt

superchain/configs/mainnet/swell.toml

@@ -17,6 +17,7 @@ max_sequencer_drift = 600
   ecotone_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
   fjord_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
   granite_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
+  holocene_time = 1752732000 # Thu 17 Jul 2025 06:00:00 UTC
 
 [optimism]
   eip1559_elasticity = 6