Refactor cast-target-field path in cast.rs

Eliminate unnecessary DataType clone and simplify the cast-validity
branches into a single boolean expression. Ensure that the behavior
and public surface remain unchanged while improving code efficiency.

Author: kosiew

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

@@ -337,18 +337,16 @@ pub(crate) fn cast_with_target_field_and_options(
     cast_options: Option<CastOptions<'static>>,
 ) -> Result<Arc<dyn PhysicalExpr>> {
     let expr_type = expr.data_type(input_schema)?;
-    let cast_type = target_field.data_type().clone();
-    let is_valid_cast = if expr_type == cast_type {
-        true
-    } else if matches!((&expr_type, &cast_type), (Struct(_), Struct(_))) {
+    let cast_type = target_field.data_type();
+    let is_valid_cast = expr_type == *cast_type
+        || match (&expr_type, cast_type) {
         // Allow struct-to-struct casts that pass name-based compatibility validation.
         // This validation is applied at planning time (now) to fail fast, rather than
         // deferring errors to execution time. The name-based casting logic will be
         // executed at runtime via ColumnarValue::cast_to.
-        can_cast_struct_types(&expr_type, &cast_type)
-    } else {
-        can_cast_types(&expr_type, &cast_type)
-    };
+            (Struct(_), Struct(_)) => can_cast_struct_types(&expr_type, cast_type),
+            _ => can_cast_types(&expr_type, cast_type),
+        };
 
     if !is_valid_cast {
         not_impl_err!("Unsupported CAST from {expr_type} to {cast_type}")