### 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
material_storage->shader_initialize(default_clip_children_shader);
		material_storage->shader_set_code(default_clip_children_shader, R"(
// Default clip children shader.
shader_type canvas_item;
render_mode unshaded;
uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
void fragment() {
	vec4 c = textureLod(screen_texture, SCREEN_UV, 0.0);
	COLOR.rgb = c.rgb;
}
)");
		default_clip_children_material = material_storage->material_allocate();
		material_storage->material_initialize(default_clip_children_material);
		material_storage->material_set_shader(default_clip_children_material, default_clip_children_shader);
	}
	default_canvas_texture = texture_storage->canvas_texture_allocate();
	texture_storage->canvas_texture_initialize(default_canvas_texture);
	state.time = 0.0;
}
RasterizerCanvasGLES3::~RasterizerCanvasGLES3() {
	singleton = nullptr;
	GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton();
	material_storage->shaders.canvas_shader.version_free(data.canvas_shader_default_version);
	shadow_render.shader.version_free(shadow_render.shader_version);
	material_storage->material_free(default_canvas_group_material);
	material_storage->shader_free(default_canvas_group_shader);
	material_storage->material_free(default_clip_children_material);
	material_storage->shader_free(default_clip_children_shader);
	singleton = nullptr;
	glDeleteBuffers(1, &data.canvas_quad_vertices);