Remove unused imports (#4436)

Co-authored-by: Francisco <fg@frang.io>

contracts/governance/extensions/GovernorTimelockCompound.sol

@@ -5,7 +5,6 @@ pragma solidity ^0.8.19;
 
 import {IGovernorTimelock} from "./IGovernorTimelock.sol";
 import {IGovernor, Governor} from "../Governor.sol";
-import {SafeCast} from "../../utils/math/SafeCast.sol";
 import {ICompoundTimelock} from "../../vendor/compound/ICompoundTimelock.sol";
 import {IERC165} from "../../interfaces/IERC165.sol";
 import {Address} from "../../utils/Address.sol";