### Godot version

4.1

### 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


https://github.com/godotengine/godot/assets/2223172/3c8ee782-9d5f-42e3-a70f-d2aa59a233dd

We correctly clamp the size to 16x16 everywhere except here (probably).

### Steps to reproduce

1. Add a class with custom icon, e.g.
```GDScript
@icon("res://icon.svg")
extends Node
class_name Icon
```
2. Add it to scene
3. Open Script Editor and drag the node to script editor

### Minimal reproduction project

N/A
if (!p_node) {
		return nullptr;
	}
	NodePath np = p_node->get_metadata(0);
	if (np == p_path) {
		return p_node;
	}
	TreeItem *children = p_node->get_first_child();
	while (children) {
		TreeItem *n = _find(children, p_path);
		if (n) {
			return n;
		}
		children = children->get_next();
	}
	return nullptr;
}
void SceneTreeEditor::set_selected(Node *p_node, bool p_emit_selected) {