fix(types): fix serde feature gates (#1121)

Author: Thoralf-M

crates/iota-sdk-types/src/move_package.rs

@@ -120,7 +120,7 @@ pub struct TypeOrigin {
     /// The name of the data type. Either refers to an enum or a struct
     /// identifier.
     // `struct_name` alias to support backwards compatibility with the old name
-    #[serde(alias = "struct_name")]
+    #[cfg_attr(feature = "serde", serde(alias = "struct_name"))]
     pub datatype_name: Identifier,
     /// ID of the package, where the given type first appeared.
     pub package: ObjectId,

crates/iota-sdk-types/src/object.rs

@@ -2,11 +2,12 @@
 // Modifications Copyright (c) 2025 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
+#[cfg(feature = "serde")]
 use std::collections::BTreeMap;
 
-use super::{
-    Address, Digest, Identifier, MovePackage, ObjectId, StructTag, TypeOrigin, UpgradeInfo, Version,
-};
+use super::{Address, Digest, MovePackage, ObjectId, StructTag, Version};
+#[cfg(feature = "serde")]
+use super::{Identifier, TypeOrigin, UpgradeInfo};
 
 /// Reference to an object
 ///