### 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
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);
		if (co->cull_mode != cull_mode) {
			if (co->cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_DISABLED) {
				glDisable(GL_CULL_FACE);
			} else {
				if (cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_DISABLED) {
					
					glEnable(GL_CULL_FACE);
				}
				glCullFace(co->cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_CLOCKWISE ? GL_FRONT : GL_BACK);
			}
			cull_mode = co->cull_mode;
		}
		glBindVertexArray(co->vertex_array);
		glDrawElements(GL_TRIANGLES, 3 * co->line_point_count, GL_UNSIGNED_SHORT, 0);
		instance = instance->next;
	}
	Transform2D to_shadow;
	to_shadow.columns[0].x = 1.0 / -(half_size * 2.0);
	to_shadow.columns[2].x = 0.5;
	cl->shadow.directional_xform = to_shadow * to_light_xform;
	glBindVertexArray(0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glDepthMask(GL_FALSE);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_SCISSOR_TEST);
	glDisable(GL_CULL_FACE);
}
void RasterizerCanvasGLES3::_update_shadow_atlas() {