### Godot version

v4.0.beta.custom_build [eaf306e0b]

### System information

Windows 10

### Issue description

Selecting a `Window` node in the Editor's SceneTree results in the message
```
editor/editor_data.cpp:1058 - Parameter "p_node" is null.
```
and the Inspector shows empty content instead of the Window's properties.

I would expect, that clicking on a node in the SceneTree lets me edit the properties of the node.

Bisecting shows that this behavior got introduced in #71770

### Steps to reproduce

1. Create a Window node
2. Click on the Window node in the Editor's SceneTree

### Minimal reproduction project

N/A
snap_node_center = !snap_node_center;
			int idx = smartsnap_config_popup->get_item_index(SNAP_USE_NODE_CENTER);
			smartsnap_config_popup->set_item_checked(idx, snap_node_center);
		} break;
		case SNAP_USE_OTHER_NODES: {
			snap_other_nodes = !snap_other_nodes;
			int idx = smartsnap_config_popup->get_item_index(SNAP_USE_OTHER_NODES);
			smartsnap_config_popup->set_item_checked(idx, snap_other_nodes);
		} break;
		case SNAP_USE_GUIDES: {
			snap_guides = !snap_guides;
			int idx = smartsnap_config_popup->get_item_index(SNAP_USE_GUIDES);
			smartsnap_config_popup->set_item_checked(idx, snap_guides);
		} break;
		case SNAP_USE_ROTATION: {
			snap_rotation = !snap_rotation;
			int idx = snap_config_menu->get_popup()->get_item_index(SNAP_USE_ROTATION);
			snap_config_menu->get_popup()->set_item_checked(idx, snap_rotation);
		} break;
		case SNAP_USE_SCALE: {
			snap_scale = !snap_scale;
			int idx = snap_config_menu->get_popup()->get_item_index(SNAP_USE_SCALE);
			snap_config_menu->get_popup()->set_item_checked(idx, snap_scale);
		} break;
		case SNAP_RELATIVE: {
			snap_relative = !snap_relative;
			int idx = snap_config_menu->get_popup()->get_item_index(SNAP_RELATIVE);
			snap_config_menu->get_popup()->set_item_checked(idx, snap_relative);
			viewport->queue_redraw();
		} break;