### 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

_
CanvasLight *cl = canvas_light_owner.get_or_null(p_rid);
	ERR_FAIL_COND(!cl);
	cl->shadow.enabled = p_enable;
}
void RasterizerCanvasGLES3::light_update_shadow(RID p_rid, int p_shadow_index, const Transform2D &p_light_xform, int p_light_mask, float p_near, float p_far, LightOccluderInstance *p_occluders) {
	GLES3::Config *config = GLES3::Config::get_singleton();
	CanvasLight *cl = canvas_light_owner.get_or_null(p_rid);
	ERR_FAIL_COND(!cl->shadow.enabled);
	_update_shadow_atlas();
	cl->shadow.z_far = p_far;
	cl->shadow.y_offset = float(p_shadow_index * 2 + 1) / float(data.max_lights_per_render * 2);
	glBindFramebuffer(GL_FRAMEBUFFER, state.shadow_fb);
	glViewport(0, p_shadow_index * 2, state.shadow_texture_size, 2);
	glDepthMask(GL_TRUE);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);
	glDisable(GL_BLEND);
	glEnable(GL_SCISSOR_TEST);
	glScissor(0, p_shadow_index * 2, state.shadow_texture_size, 2);
	glClearColor(p_far, p_far, p_far, 1.0);
	glClearDepth(1.0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glCullFace(GL_BACK);
	glDisable(GL_CULL_FACE);