### 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
glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);
	glDisable(GL_BLEND);
	glEnable(GL_SCISSOR_TEST);
	glScissor(0, p_shadow_index * 2, state.shadow_texture_size, 2);
	glClearColor(1.0, 1.0, 1.0, 1.0);
	RasterizerGLES3::clear_depth(1.0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glCullFace(GL_BACK);
	glDisable(GL_CULL_FACE);
	RS::CanvasOccluderPolygonCullMode cull_mode = RS::CANVAS_OCCLUDER_POLYGON_CULL_DISABLED;
	CanvasOcclusionShaderGLES3::ShaderVariant variant = config->float_texture_supported ? CanvasOcclusionShaderGLES3::MODE_SHADOW : CanvasOcclusionShaderGLES3::MODE_SHADOW_RGBA;
	bool success = shadow_render.shader.version_bind_shader(shadow_render.shader_version, variant);
	if (!success) {
		return;
	}
	Projection projection;
	projection.set_orthogonal(-half_size, half_size, -0.5, 0.5, 0.0, distance);
	projection = projection * Projection(Transform3D().looking_at(Vector3(0, 1, 0), Vector3(0, 0, -1)).affine_inverse());
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::PROJECTION, projection, shadow_render.shader_version, variant);
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::DIRECTION, 0.0, 1.0, shadow_render.shader_version, variant);
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::Z_FAR, distance, shadow_render.shader_version, variant);
	LightOccluderInstance *instance = p_occluders;
	while (instance) {
		OccluderPolygon *co = occluder_polygon_owner.get_or_null(instance->occluder);
		if (!co || co->vertex_array == 0 || !(p_light_mask & instance->light_mask)) {
			instance = instance->next;
			continue;
		}
		Transform2D modelview = to_light_xform * instance->xform_cache;