### Godot version

v4.0.beta17.official [c40020513]

### System information

Windows 11, OpenGL (Compatibility), RTX 2060 (31.0.15.2824)

### Issue description

I tried to make a blurred panel for a ui element with texturelod via shader:

```glsl
shader_type canvas_item;

uniform sampler2D SCREEN_TEXTURE : hint_screen_texture, filter_linear_mipmap_anisotropic;
uniform float blur_amount : hint_range(0.0, 5.0);

void fragment() {
	vec4 blurred = textureLod(SCREEN_TEXTURE, SCREEN_UV, blur_amount);
	COLOR = blurred;
}
```

but what I got instead is this:
![image](https://user-images.githubusercontent.com/72286622/217170426-49f6712d-47ef-4c53-b9f1-30d8ad868084.png)

vulkan renderer does not exhibit this issue:
![image](https://user-images.githubusercontent.com/72286622/217170565-a013c712-94f6-49d1-b9ec-091c28a7790b.png)


### Steps to reproduce

1. Add a TextureRect node
2. Add a Panel node to overlay the previously added node
3. Apply the blur shader to the panel node

### Minimal reproduction project

N/A
RenderTarget render_target;
	render_target.used_in_frame = false;
	render_target.clear_requested = false;
	Texture t;
	t.active = true;
	t.render_target = &render_target;
	t.is_render_target = true;
	render_target.texture = texture_owner.make_rid(t);
	_update_render_target(&render_target);
	return render_target_owner.make_rid(render_target);
}
void TextureStorage::render_target_free(RID p_rid) {
	RenderTarget *rt = render_target_owner.get_or_null(p_rid);
	_clear_render_target(rt);
	Texture *t = get_texture(rt->texture);
	if (t) {
		t->is_render_target = false;
		if (rt->overridden.color.is_null()) {
			texture_free(rt->texture);
		}
		
	}
	render_target_owner.free(p_rid);
}
void TextureStorage::render_target_set_position(RID p_render_target, int p_x, int p_y) {