fix: same defer-capture leak in destroyValueSlice (3 additional sites)

The same bug pattern exists for destroyValueSlice in value.go:
  - inferSliceLogicalTypeAndValue (line 398): values := make([]Value, 0, length)
  - createSliceValue             (line 459): var values []Value
  - createStructValue            (line 487): var values []Value

All three use `defer destroyValueSlice(values)` where `values` is
nil or len=0 at the defer site. The deferred cleanup iterates over
zero elements and never calls DestroyValue on the C-allocated
duckdb_value objects.

These functions are called when binding STRUCT, LIST, or ARRAY values
via Appender or prepared statements. Each call leaks one C Value
object per element/field.

Not a double-free risk: DuckDB's Create*Value functions (CreateListValue,
CreateArrayValue, CreateStructValue) deep-copy the input values via
allocValues → duckdb_create_*_value. The original Value objects remain
owned by the caller and must be destroyed separately.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hellower

value.go

@@ -395,7 +395,7 @@ func inferSliceLogicalTypeAndValue[T any](val T, array bool, length int) (mappin
 	}
 
 	values := make([]mapping.Value, 0, length)
-	defer destroyValueSlice(values)
+	defer func() { destroyValueSlice(values) }()
 
 	if len(slice) == 0 {
 		lt := mapping.CreateLogicalType(TYPE_SQLNULL)
@@ -456,7 +456,7 @@ func createSliceValue[T any](lt mapping.LogicalType, t Type, val T) (mapping.Val
 	}
 
 	var values []mapping.Value
-	defer destroyValueSlice(values)
+	defer func() { destroyValueSlice(values) }()
 
 	for _, v := range slice {
 		vv, err := createValue(childType, v)
@@ -484,7 +484,7 @@ func createStructValue(lt mapping.LogicalType, val any) (mapping.Value, error) {
 	}
 
 	var values []mapping.Value
-	defer destroyValueSlice(values)
+	defer func() { destroyValueSlice(values) }()
 
 	childCount := mapping.StructTypeChildCount(lt)
 	for i := range uint64(childCount) {