Remove AccessControlNonRevokable mock and unnecesary changelog entry (#5635)

CHANGELOG.md

@@ -8,7 +8,6 @@
 
 #### Custom error changes
 
-- Replace `AccessControlNonRevokable` with `AccessControlNonRevocable`.
 - Replace `GovernorAlreadyOverridenVote` with `GovernorAlreadyOverriddenVote`.
 - Replace `GovernorOnlyProposer` with `GovernorUnableToCancel`.
 

contracts/mocks/docs/access-control/AccessControlNonRevokableAdmin.sol

@@ -1,17 +0,0 @@
-// contracts/AccessControlNonRevokableAdmin.sol
-// SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
-
-import {AccessControl} from "../../../access/AccessControl.sol";
-
-contract AccessControlNonRevokableAdmin is AccessControl {
-    error AccessControlNonRevokable();
-
-    function revokeRole(bytes32 role, address account) public override {
-        if (role == DEFAULT_ADMIN_ROLE) {
-            revert AccessControlNonRevokable();
-        }
-
-        super.revokeRole(role, account);
-    }
-}