[Sync EN] ext/odbc: document the row default value change to null in fetch_object/array/into (PHP 8.4)

PR: `https://github.com/php/doc-en/pull/5768` (2026-08-17)

**Файлы RU для обновления**
- `reference/uodbc/functions/odbc-fetch-array.xml`
- `reference/uodbc/functions/odbc-fetch-into.xml`
- `reference/uodbc/functions/odbc-fetch-object.xml`

