### 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
item->set_custom_color(0, get_theme_color(SNAME("warning_color"), SNAME("Editor")));
		}
	} else if (marked.has(p_node)) {
		String node_name = p_node->get_name();
		if (connecting_signal) {
			node_name += " " + TTR("(Connecting From)");
		}
		item->set_text(0, node_name);
		item->set_selectable(0, marked_selectable);
		item->set_custom_color(0, get_theme_color(SNAME("accent_color"), SNAME("Editor")));
	} else if (!p_node->can_process()) {
		item->set_custom_color(0, get_theme_color(SNAME("disabled_font_color"), SNAME("Editor")));
	} else if (!marked_selectable && !marked_children_selectable) {
		Node *node = p_node;
		while (node) {
			if (marked.has(node)) {
				item->set_selectable(0, false);
				item->set_custom_color(0, get_theme_color(SNAME("error_color"), SNAME("Editor")));
				break;
			}
			node = node->get_parent();
		}
	}
	if (can_rename) { 
		String conf_warning = p_node->get_configuration_warnings_as_string();
		if (!conf_warning.is_empty()) {
			const int num_warnings = p_node->get_configuration_warnings().size();
			String warning_icon;
			if (num_warnings == 1) {
				warning_icon = SNAME("NodeWarning");