### 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
state.canvas_instance_batches.clear();
		return;
	}
	
	glBindBuffer(GL_ARRAY_BUFFER, state.canvas_instance_data_buffers[state.current_data_buffer_index].instance_buffers[state.current_instance_buffer_index]);
#ifdef WEB_ENABLED
	glBufferSubData(GL_ARRAY_BUFFER, state.last_item_index * sizeof(InstanceData), sizeof(InstanceData) * index, state.instance_data_array);
#else
	
	void *buffer = glMapBufferRange(GL_ARRAY_BUFFER, state.last_item_index * sizeof(InstanceData), index * sizeof(InstanceData), GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
	memcpy(buffer, state.instance_data_array, index * sizeof(InstanceData));
	glUnmapBuffer(GL_ARRAY_BUFFER);
#endif
	glDisable(GL_SCISSOR_TEST);
	current_clip = nullptr;
	GLES3::CanvasShaderData::BlendMode last_blend_mode = GLES3::CanvasShaderData::BLEND_MODE_MIX;
	Color last_blend_color;
	state.current_tex = RID();
	for (uint32_t i = 0; i <= state.current_batch_index; i++) {
		
		if (current_clip != state.canvas_instance_batches[i].clip) {
			current_clip = state.canvas_instance_batches[i].clip;
			if (current_clip) {
				glEnable(GL_SCISSOR_TEST);
				glScissor(current_clip->final_clip_rect.position.x, current_clip->final_clip_rect.position.y, current_clip->final_clip_rect.size.x, current_clip->final_clip_rect.size.y);
			} else {
				glDisable(GL_SCISSOR_TEST);
			}
		}
		GLES3::CanvasMaterialData *material_data = state.canvas_instance_batches[i].material_data;