### 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 (!script_typed.is_null()) {
			emit_signal(SNAME("open_script"), script_typed);
		}
	} else if (p_id == BUTTON_VISIBILITY) {
		undo_redo->create_action(TTR("Toggle Visible"));
		_toggle_visible(n);
		List<Node *> selection = editor_selection->get_selected_node_list();
		if (selection.size() > 1 && selection.find(n) != nullptr) {
			for (Node *nv : selection) {
				ERR_FAIL_COND(!nv);
				if (nv == n) {
					continue;
				}
				_toggle_visible(nv);
			}
		}
		undo_redo->commit_action();
	} else if (p_id == BUTTON_LOCK) {
		undo_redo->create_action(TTR("Unlock Node"));
		if (n->is_class("CanvasItem") || n->is_class("Node3D")) {
			undo_redo->add_do_method(n, "remove_meta", "_edit_lock_");
			undo_redo->add_undo_method(n, "set_meta", "_edit_lock_", true);
			undo_redo->add_do_method(this, "_update_tree");
			undo_redo->add_undo_method(this, "_update_tree");
			undo_redo->add_do_method(this, "emit_signal", "node_changed");
			undo_redo->add_undo_method(this, "emit_signal", "node_changed");
		}
		undo_redo->commit_action();
	} else if (p_id == BUTTON_PIN) {
		if (n->is_class("AnimationPlayer")) {