### 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
GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
	if (p_texture == RID()) {
		p_texture = default_canvas_texture;
	}
	GLES3::CanvasTexture *ct = nullptr;
	GLES3::Texture *t = texture_storage->get_texture(p_texture);
	if (t) {
		
		if (!t->canvas_texture) {
			t->canvas_texture = memnew(GLES3::CanvasTexture);
			t->canvas_texture->diffuse = p_texture;
		}
		ct = t->canvas_texture;
	} else {
		ct = texture_storage->get_canvas_texture(p_texture);
	}
	if (!ct) {
		
		_prepare_canvas_texture(default_canvas_texture, p_base_filter, p_base_repeat, r_index, r_texpixel_size);
		return;
	}