### 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

_
#include "rasterizer_canvas_gles3.h"
#ifdef GLES3_ENABLED
#include "core/os/os.h"
#include "rasterizer_scene_gles3.h"
#include "core/config/project_settings.h"
#include "core/math/geometry_2d.h"
#include "servers/rendering/rendering_server_default.h"
#include "storage/config.h"
#include "storage/material_storage.h"
#include "storage/mesh_storage.h"
#include "storage/particles_storage.h"
#include "storage/texture_storage.h"
void RasterizerCanvasGLES3::_update_transform_2d_to_mat4(const Transform2D &p_transform, float *p_mat4) {