Cast from boolean to decimal ignores eval mode: throws where Spark returns NULL in legacy/try mode #5068

Describe the bug

The native boolean-to-decimal cast ignores eval_mode entirely and throws where Spark returns NULL in legacy and try mode.

CometCast marks boolean-to-decimal as Compatible() in all eval modes (spark/src/main/scala/org/apache/comet/expressions/CometCast.scala:329-333). The native implementation cast_boolean_to_decimal (native/spark-expr/src/conversion_funcs/boolean.rs:31-58) takes no eval_mode argument: it builds 10^scale and unconditionally raises SparkError::NumericValueOutOfRange when the value does not fit the target precision.

Spark 4.1 (Cast.scala): toPrecision(Decimal.ONE, target, ROUND_HALF_UP, nullOnOverflow = !ansiEnabled), so legacy and try mode return NULL, only ANSI throws.

Since ANSI is the default in Spark 4.x, Comet accidentally matches the default, but this is a wrong-exception bug on Spark 3.x and whenever ANSI is off, and try_cast returns an error instead of NULL.

Steps to reproduce

SET spark.sql.ansi.enabled=false;
SELECT CAST(col AS DECIMAL(1,1)) FROM (SELECT true AS col);

Any target where 10^scale exceeds the precision reproduces it, e.g. DECIMAL(1,1), DECIMAL(2,2), DECIMAL(3,3).

Spark (legacy or try mode): NULL.
Comet: throws NUMERIC_VALUE_OUT_OF_RANGE.

Expected behavior

cast_boolean_to_decimal should take the eval mode and return NULL for legacy/try, error only under ANSI.

Additional context

Found by an ANSI-mode audit of all native expressions against Spark 4.1.1. Existing CometCastSuite coverage only uses non-overflowing targets (decimal(10,2), (14,4), (30,0)), which is why this was never caught.