### 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
AnimationPlayerEditor::get_singleton()->unpin();
			_update_tree();
		}
	} else if (p_id == BUTTON_GROUP) {
		undo_redo->create_action(TTR("Button Group"));
		if (n->is_class("CanvasItem") || n->is_class("Node3D")) {
			undo_redo->add_do_method(n, "remove_meta", "_edit_group_");
			undo_redo->add_undo_method(n, "set_meta", "_edit_group_", 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_WARNING) {
		String config_err = n->get_configuration_warnings_as_string();
		if (config_err.is_empty()) {
			return;
		}
		const PackedInt32Array boundaries = TS->string_get_word_breaks(config_err, "", 80);
		PackedStringArray lines;
		for (int i = 0; i < boundaries.size(); i += 2) {
			const int start = boundaries[i];
			const int end = boundaries[i + 1];
			lines.append(config_err.substr(start, end - start + 1));
		}
		warning->set_text(String("\n").join(lines));
		warning->popup_centered();
	} else if (p_id == BUTTON_SIGNALS) {
		editor_selection->clear();