### 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 (state.canvas_instance_batches.size() == 0) {
		state.canvas_instance_batches.push_back(Batch());
		return;
	}
	if (r_batch_broken || state.canvas_instance_batches[state.current_batch_index].instance_count == 0) {
		return;
	}
	r_batch_broken = true;
	
	Batch new_batch = state.canvas_instance_batches[state.current_batch_index];
	new_batch.instance_count = 0;
	new_batch.start = state.canvas_instance_batches[state.current_batch_index].start + state.canvas_instance_batches[state.current_batch_index].instance_count;
	new_batch.instance_buffer_index = state.current_instance_buffer_index;
	state.current_batch_index++;
	state.canvas_instance_batches.push_back(new_batch);
}
void RasterizerCanvasGLES3::_enable_attributes(uint32_t p_start, bool p_primitive, uint32_t p_rate) {
	uint32_t split = p_primitive ? 11 : 12;
	for (uint32_t i = 6; i < split; i++) {
		glEnableVertexAttribArray(i);
		glVertexAttribPointer(i, 4, GL_FLOAT, GL_FALSE, sizeof(InstanceData), CAST_INT_TO_UCHAR_PTR(p_start + (i - 6) * 4 * sizeof(float)));
		glVertexAttribDivisor(i, p_rate);
	}
	for (uint32_t i = split; i <= 13; i++) {
		glEnableVertexAttribArray(i);
		glVertexAttribIPointer(i, 4, GL_UNSIGNED_INT, sizeof(InstanceData), CAST_INT_TO_UCHAR_PTR(p_start + (i - 6) * 4 * sizeof(float)));
		glVertexAttribDivisor(i, p_rate);
	}
}
RID RasterizerCanvasGLES3::light_create() {