Remove code in preparation for v5.0 (#4258)

Co-authored-by: Ernesto García <ernestognw@gmail.com>
Co-authored-by: Francisco <fg@frang.io>

contracts/access/AccessControl.sol

@@ -183,30 +183,6 @@ abstract contract AccessControl is Context, IAccessControl, ERC165 {
         _revokeRole(role, account);
     }
 
-    /**
-     * @dev Grants `role` to `account`.
-     *
-     * If `account` had not been already granted `role`, emits a {RoleGranted}
-     * event. Note that unlike {grantRole}, this function doesn't perform any
-     * checks on the calling account.
-     *
-     * May emit a {RoleGranted} event.
-     *
-     * [WARNING]
-     * ====
-     * This function should only be called from the constructor when setting
-     * up the initial roles for the system.
-     *
-     * Using this function in any other way is effectively circumventing the admin
-     * system imposed by {AccessControl}.
-     * ====
-     *
-     * NOTE: This function is deprecated in favor of {_grantRole}.
-     */
-    function _setupRole(bytes32 role, address account) internal virtual {
-        _grantRole(role, account);
-    }
-
     /**
      * @dev Sets `adminRole` as ``role``'s admin role.
      *