### 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
CanvasShaderGLES3::ShaderVariant variant = state.canvas_instance_batches[i].shader_variant;
		uint64_t specialization = 0;
		specialization |= uint64_t(state.canvas_instance_batches[i].lights_disabled);
		specialization |= uint64_t(!GLES3::Config::get_singleton()->float_texture_supported) << 1;
		RID shader_version = data.canvas_shader_default_version;
		if (material_data) {
			if (material_data->shader_data->version.is_valid() && material_data->shader_data->valid) {
				
				material_data->bind_uniforms();
				shader_version = material_data->shader_data->version;
			}
		}
		bool success = GLES3::MaterialStorage::get_singleton()->shaders.canvas_shader.version_bind_shader(shader_version, variant, specialization);
		if (!success) {
			continue;
		}
		GLES3::CanvasShaderData::BlendMode blend_mode = state.canvas_instance_batches[i].blend_mode;
		Color blend_color = state.canvas_instance_batches[i].blend_color;
		if (last_blend_mode != blend_mode || last_blend_color != blend_color) {
			if (last_blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glEnable(GL_BLEND);
			} else if (blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glDisable(GL_BLEND);
			}
			switch (blend_mode) {
				case GLES3::CanvasShaderData::BLEND_MODE_DISABLED: {
					
				} break;