Fix typo in upgradeable version of README (#5987)

Co-authored-by: ernestognw <[email protected]>

Author: Amxx

scripts/upgradeable/upgradeable.patch

@@ -66,9 +66,9 @@ index 6a01f5616..168b74aa7 100644
  > [!IMPORTANT]
  > OpenZeppelin Contracts uses semantic versioning to communicate backwards compatibility of its API and storage layout. For upgradeable contracts, the storage layout of different major versions should be assumed incompatible, for example, it is unsafe to upgrade from 4.9.3 to 5.0.0. Learn more at [Backwards Compatibility](https://docs.openzeppelin.com/contracts/backwards-compatibility).
 
-++> [!NOTE]
-++> You are looking at the upgradeable variant of OpenZeppelin Contracts. Be sure to review the documentation on [Using OpenZeppelin Contracts with Upgrades](https://docs.openzeppelin.com/contracts/upgradeable).
-++
++> [!NOTE]
++> You are looking at the upgradeable variant of OpenZeppelin Contracts. Be sure to review the documentation on [Using OpenZeppelin Contracts with Upgrades](https://docs.openzeppelin.com/contracts/upgradeable).
++
  ## Overview
 
  ### Release tags