### Godot version

4.0.rc6.mono.official

### System information

macOS 12.0.1

### Issue description

Just a minor visual issue.

When opening an empty directory the focus highlight is drawn incorrectly. It looks like the UI is drawing a smaller rectangle within the main rect:
<img width="1058" alt="Bildschirmfoto 2023-02-28 um 14 13 31" src="https://user-images.githubusercontent.com/11627131/221868794-7450606d-e758-4104-8f33-182d9779d7f8.png">


This behavior also changes when you hover over other items in the view, so I'm not sure if this a general issue with the focus highlighting or just an issue in the directory view:
<img width="1052" alt="Bildschirmfoto 2023-02-28 um 14 32 54" src="https://user-images.githubusercontent.com/11627131/221869308-4756f26e-cda2-4057-be1e-7439030895dc.png">


### Steps to reproduce

1. New Project
2. Browse
3. Create Folder
4. Click or Tab to set focus on the empty directory view

### Minimal reproduction project

N/A
if (clight->shadow.enabled) {
				state.light_uniforms[index].flags |= LIGHT_FLAGS_HAS_SHADOW;
			}
			l->render_index_cache = index;
			index++;
			l = l->next_ptr;
		}
		light_count = index;
		directional_light_count = light_count;
		state.using_directional_lights = directional_light_count > 0;
	}
	
	{
		Light *l = p_light_list;
		uint32_t index = light_count;
		while (l) {
			if (index == data.max_lights_per_render) {
				l->render_index_cache = -1;
				l = l->next_ptr;
				continue;
			}
			CanvasLight *clight = canvas_light_owner.get_or_null(l->light_internal);
			if (!clight) { 
				l->render_index_cache = -1;
				l = l->next_ptr;
				ERR_CONTINUE(!clight);
			}
			Vector2 canvas_light_pos = p_canvas_transform.xform(l->xform.get_origin()); 
			state.light_uniforms[index].position[0] = canvas_light_pos.x;
			state.light_uniforms[index].position[1] = canvas_light_pos.y;