### 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
}
				index_array_gl = mesh_storage->mesh_surface_get_index_buffer(surface, 0);
				bool use_index_buffer = false;
				glBindVertexArray(vertex_array_gl);
				glBindBuffer(GL_ARRAY_BUFFER, state.canvas_instance_data_buffers[state.current_data_buffer_index].instance_buffers[state.canvas_instance_batches[p_index].instance_buffer_index]);
				uint32_t range_start = state.canvas_instance_batches[p_index].start * sizeof(InstanceData);
				_enable_attributes(range_start, false, instance_count);
				if (index_array_gl != 0) {
					glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_array_gl);
					use_index_buffer = true;
				}
				if (use_instancing) {
					if (instance_buffer == 0) {
						break;
					}
					
					glBindBuffer(GL_ARRAY_BUFFER, instance_buffer);
					glEnableVertexAttribArray(1);
					glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(0));
					glVertexAttribDivisor(1, 1);
					glEnableVertexAttribArray(2);
					glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(4 * 4));
					glVertexAttribDivisor(2, 1);
					if (instance_uses_color || instance_uses_custom_data) {
						glEnableVertexAttribArray(5);
						glVertexAttribIPointer(5, 4, GL_UNSIGNED_INT, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(instance_color_offset * sizeof(float)));
						glVertexAttribDivisor(5, 1);
					} else {
						
						uint16_t zero = Math::make_half_float(0.0f);