### 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
if (base_size < si.size.width) {
				base_size = nearest_power_of_2_templated(si.size.width);
			}
			si.texture = E.key;
			idx++;
		}
		
		itemsv.sort();
		
		int item_count = itemsv.size();
		TextureAtlas::SortItem *items = itemsv.ptrw();
		int atlas_height = 0;
		while (true) {
			Vector<int> v_offsetsv;
			v_offsetsv.resize(base_size);
			int *v_offsets = v_offsetsv.ptrw();
			memset(v_offsets, 0, sizeof(int) * base_size);
			int max_height = 0;
			for (int i = 0; i < item_count; i++) {
				
				TextureAtlas::SortItem &si = items[i];
				int best_idx = -1;
				int best_height = 0x7FFFFFFF;
				for (int j = 0; j <= base_size - si.size.width; j++) {
					int height = 0;
					for (int k = 0; k < si.size.width; k++) {
						int h = v_offsets[k + j];
						if (h > height) {
							height = h;
							if (height > best_height) {