[GPU] Fix broadcast save/load impls (openvinotoolkit#26582)

### Details:
- Fixes sporadic crash of
`KVCacheTests.smoke_multipleIterations_stateful_gather_with_initializer_cached`
test

### Jira
 - https://jira.devtools.intel.com/browse/CVS-133748

src/plugins/intel_gpu/src/graph/impls/cpu/broadcast.cpp

@@ -45,14 +45,14 @@ struct broadcast_impl : public typed_primitive_impl<broadcast> {
     void save(BinaryOutputBuffer& ob) const override {
         parent::save(ob);
         ob << make_data(&broadcast_mode, sizeof(ov::op::BroadcastModeSpec));
-        ob << make_data(&target_shape, sizeof(ov::Shape));
+        ob << target_shape;
         ob << axes_mapping;
     }
 
     void load(BinaryInputBuffer& ib) override {
         parent::load(ib);
         ib >> make_data(&broadcast_mode, sizeof(ov::op::BroadcastModeSpec));
-        ib >> make_data(&target_shape, sizeof(ov::Shape));
+        ib >> target_shape;
         ib >> axes_mapping;
     }