### 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
Color col = primitive->colors[j] * base_color;
					state.instance_data_array[r_index].colors[j * 2 + 0] = (uint32_t(Math::make_half_float(col.g)) << 16) | Math::make_half_float(col.r);
					state.instance_data_array[r_index].colors[j * 2 + 1] = (uint32_t(Math::make_half_float(col.a)) << 16) | Math::make_half_float(col.b);
				}
				_add_to_batch(r_index, r_batch_broken);
				if (primitive->point_count == 4) {
					
					_update_transform_2d_to_mat2x3(base_transform * draw_transform, state.instance_data_array[r_index].world);
					_prepare_canvas_texture(state.canvas_instance_batches[state.current_batch_index].tex, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
					for (uint32_t j = 0; j < 3; j++) {
						int offset = j == 0 ? 0 : 1;
						
						state.instance_data_array[r_index].points[j * 2 + 0] = primitive->points[j + offset].x;
						state.instance_data_array[r_index].points[j * 2 + 1] = primitive->points[j + offset].y;
						state.instance_data_array[r_index].uvs[j * 2 + 0] = primitive->uvs[j + offset].x;
						state.instance_data_array[r_index].uvs[j * 2 + 1] = primitive->uvs[j + offset].y;
						Color col = primitive->colors[j + offset] * base_color;
						state.instance_data_array[r_index].colors[j * 2 + 0] = (uint32_t(Math::make_half_float(col.g)) << 16) | Math::make_half_float(col.r);
						state.instance_data_array[r_index].colors[j * 2 + 1] = (uint32_t(Math::make_half_float(col.a)) << 16) | Math::make_half_float(col.b);
					}
					_add_to_batch(r_index, r_batch_broken);
				}
			} break;
			case Item::Command::TYPE_MESH:
			case Item::Command::TYPE_MULTIMESH:
			case Item::Command::TYPE_PARTICLES: {
				
				_new_batch(r_batch_broken);
				Color modulate(1, 1, 1, 1);
				state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_ATTRIBUTES;