### 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
shadow_tex = tex->tex_id;
		}
		glActiveTexture(GL_TEXTURE0 + GLES3::Config::get_singleton()->max_texture_image_units - 3);
		glBindTexture(GL_TEXTURE_2D, shadow_tex);
	}
	{
		
		StateBuffer state_buffer;
		Size2i ssize = texture_storage->render_target_get_size(p_to_render_target);
		
		
		
		float y_scale = texture_storage->render_target_get_override_color(p_to_render_target).is_valid() ? -2.0f : 2.0f;
		Transform3D screen_transform;
		screen_transform.translate_local(-(ssize.width / 2.0f), -(ssize.height / 2.0f), 0.0f);
		screen_transform.scale(Vector3(2.0f / ssize.width, y_scale / ssize.height, 1.0f));
		_update_transform_to_mat4(screen_transform, state_buffer.screen_transform);
		_update_transform_2d_to_mat4(p_canvas_transform, state_buffer.canvas_transform);
		Transform2D normal_transform = p_canvas_transform;
		normal_transform.columns[0].normalize();
		normal_transform.columns[1].normalize();
		normal_transform.columns[2] = Vector2();
		_update_transform_2d_to_mat4(normal_transform, state_buffer.canvas_normal_transform);
		state_buffer.canvas_modulate[0] = p_modulate.r;
		state_buffer.canvas_modulate[1] = p_modulate.g;
		state_buffer.canvas_modulate[2] = p_modulate.b;
		state_buffer.canvas_modulate[3] = p_modulate.a;
		Size2 render_target_size = texture_storage->render_target_get_size(p_to_render_target);
		state_buffer.screen_pixel_size[0] = 1.0 / render_target_size.x;
		state_buffer.screen_pixel_size[1] = 1.0 / render_target_size.y;