deploy-config: temp fix for new config

Hides new config behind a particular chain id so that it doesn't try
to be parsed in the getting started guide. We will implement a form
of fallback config in the future.

packages/contracts-bedrock/scripts/DeployConfig.s.sol

@@ -84,9 +84,12 @@ contract DeployConfig is Script {
         eip1559Denominator = stdJson.readUint(_json, "$.eip1559Denominator");
         eip1559Elasticity = stdJson.readUint(_json, "$.eip1559Elasticity");
         l2GenesisRegolithTimeOffset = stdJson.readUint(_json, "$.l2GenesisRegolithTimeOffset");
+
+        if (block.chainid == 900) {
             faultGameAbsolutePrestate = stdJson.readUint(_json, "$.faultGameAbsolutePrestate");
             faultGameMaxDepth = stdJson.readUint(_json, "$.faultGameMaxDepth");
         }
+    }
 
     function l1StartingBlockTag() public returns (bytes32) {
         try vm.parseJsonBytes32(_json, "$.l1StartingBlockTag") returns (bytes32 tag) {