### 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
bottom_panel_updating = true;
		for (int i = 0; i < bottom_panel_items.size(); i++) {
			bottom_panel_items[i].button->set_pressed(i == p_idx);
			bottom_panel_items[i].control->set_visible(i == p_idx);
		}
		if (EditorDebuggerNode::get_singleton() == bottom_panel_items[p_idx].control) {
			
			bottom_panel->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("BottomPanelDebuggerOverride"), SNAME("EditorStyles")));
		} else {
			bottom_panel->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("BottomPanel"), SNAME("EditorStyles")));
		}
		center_split->set_dragger_visibility(SplitContainer::DRAGGER_VISIBLE);
		center_split->set_collapsed(false);
		if (bottom_panel_raise->is_pressed()) {
			top_split->hide();
		}
		bottom_panel_raise->show();
	} else {
		bottom_panel->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("BottomPanel"), SNAME("EditorStyles")));
		bottom_panel_items[p_idx].button->set_pressed(false);
		bottom_panel_items[p_idx].control->set_visible(false);
		center_split->set_dragger_visibility(SplitContainer::DRAGGER_HIDDEN);
		center_split->set_collapsed(true);
		bottom_panel_raise->hide();
		if (bottom_panel_raise->is_pressed()) {
			top_split->show();
		}
	}
}
void EditorNode::set_docks_visible(bool p_show) {