fix(protocol): fix OZ bump side effects

packages/protocol/contracts/L1/gov/TaikoGovernor.sol

@@ -14,10 +14,8 @@
 
 pragma solidity 0.8.24;
 
-import "@openzeppelin/contracts-upgradeable/governance/GovernorUpgradeable.sol";
 import
     "@openzeppelin/contracts-upgradeable/governance/compatibility/GovernorCompatibilityBravoUpgradeable.sol";
-import "@openzeppelin/contracts-upgradeable/governance/extensions/GovernorVotesUpgradeable.sol";
 import
     "@openzeppelin/contracts-upgradeable/governance/extensions/GovernorVotesQuorumFractionUpgradeable.sol";
 import
@@ -26,9 +24,7 @@ import "../../common/OwnerUUPSUpgradable.sol";
 
 contract TaikoGovernor is
     OwnerUUPSUpgradable,
-    GovernorUpgradeable,
     GovernorCompatibilityBravoUpgradeable,
-    GovernorVotesUpgradeable,
     GovernorVotesQuorumFractionUpgradeable,
     GovernorTimelockControlUpgradeable
 {
@@ -42,8 +38,7 @@ contract TaikoGovernor is
         initializer
     {
         __OwnerUUPSUpgradable_init();
-        __Governor_init("TaikoGovernor");
-        __GovernorCompatibilityBravo_init();
+        __Governor_init("Taiko");
         __GovernorVotes_init(_token);
         __GovernorVotesQuorumFraction_init(4);
         __GovernorTimelockControl_init(_timelock);
@@ -68,7 +63,8 @@ contract TaikoGovernor is
         override(GovernorUpgradeable, GovernorTimelockControlUpgradeable, IERC165Upgradeable)
         returns (bool)
     {
-        return super.supportsInterface(interfaceId);
+        return interfaceId == type(IGovernorUpgradeable).interfaceId
+            || super.supportsInterface(interfaceId);
     }
 
     function state(uint256 proposalId)
@@ -96,6 +92,23 @@ contract TaikoGovernor is
         return 1_000_000_000 ether / 10_000; // 0.01% of Taiko Token
     }
 
+    /**
+     * @dev See {IGovernor-cancel}.
+     */
+    function cancel(
+        address[] memory targets,
+        uint256[] memory values,
+        bytes[] memory calldatas,
+        bytes32 descriptionHash
+    )
+        public
+        virtual
+        override(IGovernorUpgradeable, GovernorUpgradeable, GovernorCompatibilityBravoUpgradeable)
+        returns (uint256)
+    {
+        return super.cancel(targets, values, calldatas, descriptionHash);
+    }
+
     function _execute(
         uint256 proposalId,
         address[] memory targets,

packages/protocol/test/L1/gov/TaikoGovernor.t.sol

@@ -91,7 +91,7 @@ contract TestTaikoGovernor is TaikoL1TestBase {
         assertEq(taikoGovernor.quorumDenominator(), 100, "Incorrect quorum denominator");
 
         // GovernorUpgradeable
-        assertEq(taikoGovernor.name(), "TaikoGovernor", "Incorrect name");
+        assertEq(taikoGovernor.name(), "Taiko", "Incorrect name");
         assertEq(taikoGovernor.version(), "1", "Incorrect version");
 
         // GovernorVotesUpgradeable

packages/protocol/test/common/EssentialContract.t.sol

@@ -27,6 +27,11 @@ contract Target2 is Target1 {
 }
 
 contract TestOwnerUUPSUpgradable is TaikoTest {
+    /// @dev This is how we can query the admin - because from v.4.9.5 external admin() function
+    /// does not exist anymore.
+    bytes32 internal constant _ADMIN_SLOT =
+        0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
+
     function test_essential_behind_1967_proxy() external {
         bytes memory data = abi.encodeCall(Target1.init, ());
         vm.startPrank(Alice);
@@ -80,18 +85,10 @@ contract TestOwnerUUPSUpgradable is TaikoTest {
         vm.prank(Carol);
         assertEq(target.owner(), Alice);
 
-        // Only Bob can call admin()
-        vm.prank(Bob);
-        assertEq(proxy.admin(), Bob);
-
-        // Other people, including Alice, cannot call admin()
-        vm.prank(Alice);
-        vm.expectRevert();
-        proxy.admin();
-
-        vm.prank(Carol);
-        vm.expectRevert();
-        proxy.admin();
+        // Admin can be queried via storage slot only - no other way.
+        bytes32 adminSlotValue = vm.load(address(proxy), _ADMIN_SLOT);
+        address admin = address(uint160(uint256(adminSlotValue)));
+        assertEq(admin, Bob);
 
         // Alice can adjust();
         vm.prank(Alice);