### 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
PolygonBuffers pb;
	glGenBuffers(1, &pb.vertex_buffer);
	glGenVertexArrays(1, &pb.vertex_array);
	glBindVertexArray(pb.vertex_array);
	pb.count = vertex_count;
	pb.index_buffer = 0;
	uint32_t buffer_size = stride * p_points.size();
	Vector<uint8_t> polygon_buffer;
	polygon_buffer.resize(buffer_size * sizeof(float));
	{
		glBindBuffer(GL_ARRAY_BUFFER, pb.vertex_buffer);
		uint8_t *r = polygon_buffer.ptrw();
		float *fptr = reinterpret_cast<float *>(r);
		uint32_t *uptr = (uint32_t *)r;
		uint32_t base_offset = 0;
		{
			
			glEnableVertexAttribArray(RS::ARRAY_VERTEX);
			glVertexAttribPointer(RS::ARRAY_VERTEX, 2, GL_FLOAT, GL_FALSE, stride * sizeof(float), nullptr);
			const Vector2 *points_ptr = p_points.ptr();
			for (uint32_t i = 0; i < vertex_count; i++) {
				fptr[base_offset + i * stride + 0] = points_ptr[i].x;
				fptr[base_offset + i * stride + 1] = points_ptr[i].y;
			}
			base_offset += 2;
		}
		
		if ((uint32_t)p_colors.size() == vertex_count) {
			glEnableVertexAttribArray(RS::ARRAY_COLOR);
			glVertexAttribPointer(RS::ARRAY_COLOR, 4, GL_FLOAT, GL_FALSE, stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(base_offset * sizeof(float)));