### Godot version

v4.0.beta9.official [e780dc332]

### System information

macOS Ventura 13.0.1 (Intel), Radeon Pro 580 8 GB

### Issue description

When setting the size of a SubViewport (that is inside the corresponding SubViewportContainer) to zero, the editor crashes instantly.

**But it only happens when I set the size of the SubViewport by sliding the values.**

You can see what happens in this video:


https://user-images.githubusercontent.com/91340577/209363880-503d3dff-80e1-4e9e-bb57-d059fdbfeed0.mp4

At the end of the video you can see the crash message of macOS reading: _Godot quit unexpectedly._

If I write the number zero (or any negative) to the values of the SubViewport size, the crash doesn't happens.

### Steps to reproduce

1. Add a SubViewportContainer
2. Add a SubViewport as a child of the SubViewportContainer
3. Set the size of the SubViewport to zero **by sliding** the X or the Y value.

### Minimal reproduction project

1. Open the project
2. Go to the Control.tscn scene
3. Select the SubViewport node
4. Slide the X or Y values of the size to zero

[SubViewportCrash.zip](https://github.com/godotengine/godot/files/10296101/SubViewportCrash.zip)
if (gui.subwindow_drag != SUB_WINDOW_DRAG_DISABLED) {
		ERR_FAIL_COND_V(gui.subwindow_focused == nullptr, false);
		Ref<InputEventMouseButton> mb = p_event;
		if (mb.is_valid() && !mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT) {
			if (gui.subwindow_drag == SUB_WINDOW_DRAG_CLOSE) {
				if (gui.subwindow_drag_close_rect.has_point(mb->get_position())) {
					
					gui.subwindow_focused->_event_callback(DisplayServer::WINDOW_EVENT_CLOSE_REQUEST);
				}
			}
			gui.subwindow_drag = SUB_WINDOW_DRAG_DISABLED;
			if (gui.subwindow_focused != nullptr) { 
				_sub_window_update(gui.subwindow_focused);
			}
		}
		Ref<InputEventMouseMotion> mm = p_event;
		if (mm.is_valid()) {
			if (gui.subwindow_drag == SUB_WINDOW_DRAG_MOVE) {
				Vector2 diff = mm->get_position() - gui.subwindow_drag_from;
				Rect2i new_rect(gui.subwindow_drag_pos + diff, gui.subwindow_focused->get_size());
				if (gui.subwindow_focused->is_clamped_to_embedder()) {
					Size2i limit = get_visible_rect().size;
					if (new_rect.position.x + new_rect.size.x > limit.x) {
						new_rect.position.x = limit.x - new_rect.size.x;
					}
					if (new_rect.position.y + new_rect.size.y > limit.y) {
						new_rect.position.y = limit.y - new_rect.size.y;