### Godot version

4.1.1 stable

### System information

Windows 10

### Issue description

this is the default size loaded on startup 1024 which seems fine but it actually have loaded the default [2048] and ignored the size in project settings
![image](https://github.com/godotengine/godot/assets/53877170/c8c71de7-468a-487f-8e6c-dba1ce0f8fa5)

changing it now to any size will break it 
[2048]
![image](https://github.com/godotengine/godot/assets/53877170/3082ff09-b7d7-41f7-8fbb-813074a54135)

[512]
![image](https://github.com/godotengine/godot/assets/53877170/5ea4620f-52b5-4d0e-a5f5-747e777cd59d)


### Steps to reproduce

change 2d shadow atlas size in project settings while using compatibility renderer. 

### Minimal reproduction project

_
GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
	if (p_texture == RID()) {
		p_texture = default_canvas_texture;
	}
	GLES3::CanvasTexture *ct = nullptr;
	GLES3::Texture *t = texture_storage->get_texture(p_texture);
	if (t) {
		
		if (!t->canvas_texture) {
			t->canvas_texture = memnew(GLES3::CanvasTexture);
			t->canvas_texture->diffuse = p_texture;
		}
		ct = t->canvas_texture;
	} else {
		ct = texture_storage->get_canvas_texture(p_texture);
	}
	if (!ct) {
		
		_prepare_canvas_texture(default_canvas_texture, p_base_filter, p_base_repeat, r_index, r_texpixel_size);
		return;
	}