### 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
glEnableVertexAttribArray(0);
		glBindVertexArray(0);
		glBindBuffer(GL_ARRAY_BUFFER, 0); 
	}
	{
		
		glGenBuffers(1, &data.particle_quad_vertices);
		glBindBuffer(GL_ARRAY_BUFFER, data.particle_quad_vertices);
		{
			
			const float qv[16] = {
				-0.5, -0.5,
				0.0, 0.0,
				-0.5, 0.5,
				0.0, 1.0,
				0.5, 0.5,
				1.0, 1.0,
				0.5, -0.5,
				1.0, 0.0
			};
			glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 16, qv, GL_STATIC_DRAW);
		}
		glBindBuffer(GL_ARRAY_BUFFER, 0); 
		glGenVertexArrays(1, &data.particle_quad_array);
		glBindVertexArray(data.particle_quad_array);
		glBindBuffer(GL_ARRAY_BUFFER, data.particle_quad_vertices);
		glEnableVertexAttribArray(RS::ARRAY_VERTEX);
		glVertexAttribPointer(RS::ARRAY_VERTEX, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, nullptr);
		glEnableVertexAttribArray(RS::ARRAY_TEX_UV);
		glVertexAttribPointer(RS::ARRAY_TEX_UV, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, CAST_INT_TO_UCHAR_PTR(8));