### 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

_
GLuint new_buffers[3];
	glGenBuffers(3, new_buffers);
	
	glBindBuffer(GL_ARRAY_BUFFER, new_buffers[0]);
	GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_ARRAY_BUFFER, new_buffers[0], data.max_instance_buffer_size, nullptr, GL_STREAM_DRAW, "2D Batch UBO[" + itos(state.current_data_buffer_index) + "][0]");
	
	glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[1]);
	GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_UNIFORM_BUFFER, new_buffers[1], sizeof(LightUniform) * data.max_lights_per_render, nullptr, GL_STREAM_DRAW, "2D Lights UBO[" + itos(state.current_data_buffer_index) + "]");
	
	glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[2]);
	GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_UNIFORM_BUFFER, new_buffers[2], sizeof(StateBuffer), nullptr, GL_STREAM_DRAW, "2D State UBO[" + itos(state.current_data_buffer_index) + "]");
	state.current_data_buffer_index = (state.current_data_buffer_index + 1);
	DataBuffer db;
	db.instance_buffers.push_back(new_buffers[0]);
	db.light_ubo = new_buffers[1];
	db.state_ubo = new_buffers[2];
	db.last_frame_used = RSG::rasterizer->get_frame_number();
	state.canvas_instance_data_buffers.insert(state.current_data_buffer_index, db);
	state.current_data_buffer_index = state.current_data_buffer_index % state.canvas_instance_data_buffers.size();
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_UNIFORM_BUFFER, 0);
}
void RasterizerCanvasGLES3::_allocate_instance_buffer() {