### 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
ERR_FAIL_COND(img.is_null());
	if (texture->resize_to_po2) {
		if (p_image->is_compressed()) {
			ERR_PRINT("Texture '" + texture->path + "' is required to be a power of 2 because it uses either mipmaps or repeat, so it was decompressed. This will hurt performance and memory usage.");
		}
		if (img == p_image) {
			img = img->duplicate();
		}
		img->resize_to_po2(false);
	}
	GLenum blit_target = (texture->target == GL_TEXTURE_CUBE_MAP) ? _cube_side_enum[p_layer] : texture->target;
	Vector<uint8_t> read = img->get_data();
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(texture->target, texture->tex_id);
#ifndef WEB_ENABLED
	switch (texture->format) {
#ifdef GLES_OVER_GL
		case Image::FORMAT_L8: {
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_R, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_G, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_B, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_ONE);
		} break;
		case Image::FORMAT_LA8: {
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_R, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_G, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_B, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_GREEN);
		} break;
#endif