### Godot version

v4.2.beta1.official [b1371806a]

### System information

Ubuntu 22.04.3 LTS 22.04 - X11 - GLES3 (Compatibility) - AMD Radeon RX 560 Series (polaris11, LLVM 15.0.7, DRM 3.42, 5.15.0-88-generic) () - AMD Ryzen 3 1200 Quad-Core Processor (4 Threads)

### Issue description

![image](https://github.com/godotengine/godot/assets/1330325/7a986599-5a68-42a4-beb1-5d3b4bf7db6b)
![image](https://github.com/godotengine/godot/assets/1330325/e8b8546b-b47b-4add-9567-7f70709ab03c)

Culling 3D goes bellow 60 fps even with just about 50 simple animated models. With v4.2.dev6.official [57a6813bb] many more models can be spawned without fps drop. However, both versions do show high cpu usage for culling 3D. Without animations there's barely any usage.

### Steps to reproduce

Spawn models with animation with the Compatibility renderer.

### Minimal reproduction project

[CullMRP.zip](https://github.com/godotengine/godot/files/13400514/CullMRP.zip)

}
GLES3::MaterialData *GLES3::_create_canvas_material_func(ShaderData *p_shader) {
	CanvasMaterialData *material_data = memnew(CanvasMaterialData);
	material_data->shader_data = static_cast<CanvasShaderData *>(p_shader);
	
	return material_data;
}
void SkyShaderData::set_code(const String &p_code) {
	
	code = p_code;
	valid = false;
	ubo_size = 0;
	uniforms.clear();
	uses_time = false;
	uses_position = false;
	uses_half_res = false;
	uses_quarter_res = false;
	uses_light = false;
	if (code.is_empty()) {
		return; 
	}
	ShaderCompiler::GeneratedCode gen_code;
	ShaderCompiler::IdentifierActions actions;
	actions.entry_point_stages["sky"] = ShaderCompiler::STAGE_FRAGMENT;
	actions.render_mode_flags["use_half_res_pass"] = &uses_half_res;
	actions.render_mode_flags["use_quarter_res_pass"] = &uses_quarter_res;
	actions.usage_flag_pointers["TIME"] = &uses_time;