### 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.current_instance_buffer_index++;
	if (int(state.current_instance_buffer_index) < state.canvas_instance_data_buffers[state.current_data_buffer_index].instance_buffers.size()) {
		
		return;
	}
	GLuint new_buffer;
	glGenBuffers(1, &new_buffer);
	glBindBuffer(GL_ARRAY_BUFFER, new_buffer);
	GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_ARRAY_BUFFER, new_buffer, data.max_instance_buffer_size, nullptr, GL_STREAM_DRAW, "Batch UBO[" + itos(state.current_data_buffer_index) + "][" + itos(state.canvas_instance_data_buffers[state.current_data_buffer_index].instance_buffers.size()) + "]");
	state.canvas_instance_data_buffers[state.current_data_buffer_index].instance_buffers.push_back(new_buffer);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void RasterizerCanvasGLES3::set_time(double p_time) {