nulls first/last transformation for mysql is incorrect in the context of `RANGE` windows about sqlglot HOT 5 CLOSED

In [7]: sg.parse_one("select x from t order by 1 nulls last", read="duckdb").sql("mysql")
Out[7]: 'SELECT x FROM t ORDER BY CASE WHEN 1 IS NULL THEN 1 ELSE 0 END, 1'

python -m sqlglot "select sum(x) over (order by 1 nulls last range between 1 preceding and current row)" --read=duckdb --write=mysql

'NULLS LAST' not supported with positional ordering
SELECT
  SUM(`x`) OVER (ORDER BY 1 range BETWEEN 1 preceding AND CURRENT ROW)

❯ python -m sqlglot "select sum(x) over (order by x nulls last range between 1 preceding and current row)" --read=duckdb --write=mysql
SELECT
  SUM(`x`) OVER (ORDER BY CASE WHEN `x` IS NULL THEN 1 ELSE 0 END, `x` range BETWEEN 1 preceding AND CURRENT ROW)