Fix minor mistake in GovernorTimelockAccess documentation (#4609)

contracts/governance/extensions/GovernorTimelockAccess.sol

@@ -44,7 +44,7 @@ abstract contract GovernorTimelockAccess is Governor {
         // We use mappings instead of arrays because it allows us to pack values in storage more tightly without
         // storing the length redundantly.
         // We pack 8 operations' data in each bucket. Each uint32 value is set to 1 upon proposal creation if it has
-        // to be scheduled and executed through the manager. Upon queuing, the value is set to nonce + 1, where the
+        // to be scheduled and executed through the manager. Upon queuing, the value is set to nonce + 2, where the
         // nonce is received from the manager when scheduling the operation.
         mapping(uint256 operationBucket => uint32[8]) managerData;
     }