### 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 (material.is_null()) {
					if (ci->canvas_group->mode == RS::CANVAS_GROUP_MODE_CLIP_ONLY) {
						material = default_clip_children_material;
					} else {
						material = default_canvas_group_material;
					}
				}
			}
		}
		if (material != state.canvas_instance_batches[state.current_batch_index].material) {
			_new_batch(batch_broken);
			GLES3::CanvasMaterialData *material_data = nullptr;
			if (material.is_valid()) {
				material_data = static_cast<GLES3::CanvasMaterialData *>(material_storage->material_get_data(material, RS::SHADER_CANVAS_ITEM));
			}
			shader_data_cache = nullptr;
			if (material_data) {
				if (material_data->shader_data->version.is_valid() && material_data->shader_data->valid) {
					shader_data_cache = material_data->shader_data;
				}
			}
			state.canvas_instance_batches[state.current_batch_index].material = material;
			state.canvas_instance_batches[state.current_batch_index].material_data = material_data;
		}
		GLES3::CanvasShaderData::BlendMode blend_mode = shader_data_cache ? shader_data_cache->blend_mode : GLES3::CanvasShaderData::BLEND_MODE_MIX;
		_record_item_commands(ci, p_to_render_target, p_canvas_transform_inverse, current_clip, blend_mode, p_lights, index, batch_broken, r_sdf_used);
	}
	if (index == 0) {
		
		state.current_batch_index = 0;