### 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 (canvas_light_owner.owns(p_rid)) {
		CanvasLight *cl = canvas_light_owner.get_or_null(p_rid);
		ERR_FAIL_NULL_V(cl, false);
		canvas_light_owner.free(p_rid);
	} else if (occluder_polygon_owner.owns(p_rid)) {
		occluder_polygon_set_shape(p_rid, Vector<Vector2>(), false);
		occluder_polygon_owner.free(p_rid);
	} else {
		return false;
	}
	return true;
}
void RasterizerCanvasGLES3::update() {