### 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
back_buffer_rect = Rect2();
						backbuffer_gen_mipmaps = md->shader_data->uses_screen_texture_mipmaps;
					} else if (!material_screen_texture_mipmaps_cached) {
						backbuffer_gen_mipmaps = md->shader_data->uses_screen_texture_mipmaps;
					}
				}
				if (md->shader_data->uses_sdf) {
					r_sdf_used = true;
				}
				if (md->shader_data->uses_time) {
					time_used = true;
				}
			}
		}
		if (ci->skeleton.is_valid()) {
			const Item::Command *c = ci->commands;
			while (c) {
				if (c->type == Item::Command::TYPE_MESH) {
					const Item::CommandMesh *cm = static_cast<const Item::CommandMesh *>(c);
					if (cm->mesh_instance.is_valid()) {
						mesh_storage->mesh_instance_check_for_update(cm->mesh_instance);
						mesh_storage->mesh_instance_set_canvas_item_transform(cm->mesh_instance, canvas_transform_inverse * ci->final_transform);
						update_skeletons = true;
					}
				}
				c = c->next;
			}
		}
		if (ci->canvas_group_owner != nullptr) {
			if (canvas_group_owner == nullptr) {