### 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
glDisable(GL_SCISSOR_TEST);
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClear(GL_COLOR_BUFFER_BIT);
	CanvasOcclusionShaderGLES3::ShaderVariant variant = CanvasOcclusionShaderGLES3::MODE_SDF;
	bool success = shadow_render.shader.version_bind_shader(shadow_render.shader_version, variant);
	if (!success) {
		return;
	}
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::PROJECTION, Projection(), shadow_render.shader_version, variant);
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::DIRECTION, 0.0, 0.0, shadow_render.shader_version, variant);
	shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::Z_FAR, 0.0, shadow_render.shader_version, variant);
	LightOccluderInstance *instance = p_occluders;
	while (instance) {
		OccluderPolygon *oc = occluder_polygon_owner.get_or_null(instance->occluder);
		if (!oc || oc->sdf_vertex_array == 0) {
			instance = instance->next;
			continue;
		}
		Transform2D modelview = to_clip * instance->xform_cache;
		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::MODELVIEW1, modelview.columns[0][0], modelview.columns[1][0], 0, modelview.columns[2][0], shadow_render.shader_version, variant);
		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::MODELVIEW2, modelview.columns[0][1], modelview.columns[1][1], 0, modelview.columns[2][1], shadow_render.shader_version, variant);
		glBindVertexArray(oc->sdf_vertex_array);
		glDrawElements(oc->sdf_is_lines ? GL_LINES : GL_TRIANGLES, oc->sdf_index_count, GL_UNSIGNED_INT, 0);
		instance = instance->next;
	}
	texture_storage->render_target_sdf_process(p_render_target); 
	glBindVertexArray(0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
RID RasterizerCanvasGLES3::occluder_polygon_create() {