`StockClosing.get_sle_entries` filtered `Stock Closing Balance` by a
`closing_stock_balance` column that does not exist; the link field back to
the closing entry is `stock_closing_entry`. As a result every Stock
Closing Entry created after the first one failed with
`OperationalError (1054, "Unknown column 'closing_stock_balance'")`, since
the previous-balance branch only runs once an earlier closing exists.
Fixes#54819
8e627db785