Reordered CastColumnExpr::build to validate Column index/field against

the input schema before resolving the expression data type, preserving
existing type compatibility checks and error messages.

Author: kosiew

datafusion/physical-expr/src/expressions/cast_column.rs

@@ -104,14 +104,6 @@ impl CastColumnExpr {
         input_schema: Arc<Schema>,
     ) -> Result<Self> {
         let cast_options = normalize_cast_options(cast_options);
-        let expr_data_type = expr.data_type(input_schema.as_ref())?;
-        if input_field.data_type() != &expr_data_type {
-            return plan_err!(
-                "CastColumnExpr input field data type '{}' does not match expression data type '{}'",
-                input_field.data_type(),
-                expr_data_type
-            );
-        }
         if let Some(column) = expr.as_any().downcast_ref::<Column>() {
             let fields = input_schema.fields();
             let Some(schema_field) = fields.get(column.index()) else {
@@ -134,6 +126,14 @@ impl CastColumnExpr {
                 );
             }
         }
+        let expr_data_type = expr.data_type(input_schema.as_ref())?;
+        if input_field.data_type() != &expr_data_type {
+            return plan_err!(
+                "CastColumnExpr input field data type '{}' does not match expression data type '{}'",
+                input_field.data_type(),
+                expr_data_type
+            );
+        }
 
         match (input_field.data_type(), target_field.data_type()) {
             (DataType::Struct(source_fields), DataType::Struct(target_fields)) => {