refactor: minimum updates

src/v2/FiatTokenV2.sol

@@ -3,32 +3,14 @@ pragma solidity 0.8.20;
 
 import "../v1/FiatTokenV1.sol";
 
-error InvalidReInitialization(address addr);
-
 /// @custom:security-contact [email protected]
 contract FiatTokenV2 is FiatTokenV1 {
-    uint8 internal _initializedVersion;
     bytes32 public constant BURNER_ROLE = keccak256("BURNER_ROLE");
 
-    function initializeV2(address burner) external {
-        if (_initializedVersion > 0) {
-            revert InvalidReInitialization(msg.sender);
-        }
-
-        _grantRole(BURNER_ROLE, burner);
-
-        _initializedVersion = 1;
-    }
-
-    function burnBurner(uint256 value) public onlyRole(BURNER_ROLE) {
+    function burnByBurner(uint256 value) public onlyRole(BURNER_ROLE) {
         _burn(_msgSender(), value);
     }
 
-    function burnFromBurner(address account, uint256 value) public onlyRole(BURNER_ROLE) {
-        _spendAllowance(account, _msgSender(), value);
-        _burn(account, value);
-    }
-
     function version() public pure virtual override(FiatTokenV1) returns (string memory) {
         return "2";
     }

test/v1/FiatTokenV1.t.sol

@@ -16,7 +16,6 @@ import {Upgrades, Options} from "openzeppelin-foundry-upgrades/Upgrades.sol";
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import {CallerBlacklisted} from "../../src/v1/BlacklistableV1.sol";
 import {Ramen} from "../../src/mocks/Ramen.sol";
-// import {FiatTokenV99} from "../../src/mocks/FiatTokenV99.sol";
 
 // mock contract to test upgrades
 contract FiatTokenV99 is FiatTokenV1 {