[13.x] Document changes to oauth_clients table in upgrade guide

UPGRADE.md

@@ -97,6 +97,18 @@ The JSON API provided by Passport has been deprecated. If you need to continue u
         Passport::$registersJsonApiRoutes = true;
     }
 
+### OAuth Client Table Changes (Optional)
+
+PR: https://github.com/laravel/passport/pull/1744, https://github.com/laravel/passport/pull/1797
+
+Passport's `oauth_clients` table has been changed in several ways:
+
+- The `user_id` column has been replaced by the `owner_type` and `owner_id` columns.
+- The `redirect` column has been replaced by the `redirect_uris` column. The new column needs to store an array of URLs.
+- The `personal_access_client` and `password_client` columns have been replaced by the `grant_types` column. The new column needs to store an array of OAuth 2 grant types.
+
+Passport's `Laravel\Passport\Database\Factories\ClientFactory` factory class has been updated to reflect the changes to this table. If you do not want to make these changes to your application's `oauth_clients` table, you may use the [old Client factory class](https://github.com/laravel/passport/blob/12.x/database/factories/ClientFactory.php).
+
 ## Upgrading To 12.0 From 11.x
 
 ### Migration Changes