fix: use roll instead of rollFork

Author: anna-carroll

test/host/Zenith.t.sol

@@ -37,7 +37,7 @@ contract ZenithTest is SignetStdTest {
 
         // advance to next block number to avoid the possibility during fork testing
         // that a rollup block was already submitted in the current block
-        vm.rollFork(block.number + 1);
+        vm.roll(block.number + 1);
 
         // set default block values
         header.rollupChainId = ROLLUP_CHAIN_ID;