### Godot version

4.1 rc3

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

This™
![image](https://github.com/godotengine/godot/assets/2223172/cb33110f-a5b0-400a-951f-3fa425f05714)

It can still happen, but it's more difficult to trigger.

### Steps to reproduce

1. Create a new scene with a Control node
2. Add Theme to the Control
3. Open Theme Editor
4. Clear the `theme` property in Control
5. Save, with Theme Editor opened
6. Restart

### Minimal reproduction project

N/A
List<String> property_names;
						for (const PropertyInfo &E2 : pinfo) {
							if (E2.usage & PROPERTY_USAGE_STORAGE) {
								property_names.push_back(E2.name);
							}
						}
						
						for (const KeyValue<StringName, Variant> &E2 : E.value.property_table) {
							if (property_names.find(E2.key)) {
								modifiable_node->set(E2.key, E2.value);
							}
						}
						
						for (const ConnectionWithNodePath &E2 : E.value.connections_to) {
							Connection conn = E2.connection;
							
							Node *target_node = cast_to<Node>(conn.callable.get_object());
							
							
							
							if (!target_node || !target_node->is_queued_for_deletion()) {
								target_node = modifiable_node->get_node_or_null(E2.node_path);
							}
							if (target_node) {
								
								Callable new_callable = Callable(target_node, conn.callable.get_method());
								if (!modifiable_node->is_connected(conn.signal.get_name(), new_callable)) {
									ERR_FAIL_COND(modifiable_node->connect(conn.signal.get_name(), new_callable, conn.flags) != OK);
								}
							}