### 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

_
p_mat4[0] = p_transform.columns[0][0];
	p_mat4[1] = p_transform.columns[0][1];
	p_mat4[2] = 0;
	p_mat4[3] = 0;
	p_mat4[4] = p_transform.columns[1][0];
	p_mat4[5] = p_transform.columns[1][1];
	p_mat4[6] = 0;
	p_mat4[7] = 0;
	p_mat4[8] = 0;
	p_mat4[9] = 0;
	p_mat4[10] = 1;
	p_mat4[11] = 0;
	p_mat4[12] = p_transform.columns[2][0];
	p_mat4[13] = p_transform.columns[2][1];
	p_mat4[14] = 0;
	p_mat4[15] = 1;
}
void RasterizerCanvasGLES3::_update_transform_2d_to_mat2x4(const Transform2D &p_transform, float *p_mat2x4) {