### 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
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_dir = l->xform_cache.columns[1].normalized();
			state.light_uniforms[index].position[0] = -canvas_light_dir.x;
			state.light_uniforms[index].position[1] = -canvas_light_dir.y;
			_update_transform_2d_to_mat2x4(clight->shadow.directional_xform, state.light_uniforms[index].shadow_matrix);
			state.light_uniforms[index].height = l->height; 
			for (int i = 0; i < 4; i++) {
				state.light_uniforms[index].shadow_color[i] = uint8_t(CLAMP(int32_t(l->shadow_color[i] * 255.0), 0, 255));
				state.light_uniforms[index].color[i] = l->color[i];
			}
			state.light_uniforms[index].color[3] *= l->energy; 
			if (state.shadow_fb != 0) {
				state.light_uniforms[index].shadow_pixel_size = (1.0 / state.shadow_texture_size) * (1.0 + l->shadow_smooth);
				state.light_uniforms[index].shadow_z_far_inv = 1.0 / clight->shadow.z_far;
				state.light_uniforms[index].shadow_y_ofs = clight->shadow.y_offset;
			} else {
				state.light_uniforms[index].shadow_pixel_size = 1.0;
				state.light_uniforms[index].shadow_z_far_inv = 1.0;
				state.light_uniforms[index].shadow_y_ofs = 0;
			}
			state.light_uniforms[index].flags = l->blend_mode << LIGHT_FLAGS_BLEND_SHIFT;
			state.light_uniforms[index].flags |= l->shadow_filter << LIGHT_FLAGS_FILTER_SHIFT;