### Godot version

v4.0.beta.custom_build [291add339]

### System information

Windows 10, Forward+, NVIDIA GeForce GTX 1050 Ti (31.0.15.1694)

### Issue description

I was testing if #69669 was solved by #70418, which it seemed to be. However, I got a wall of errors at the same time.

In the minimal reproduction project below in this Issue, I get errors when instantiating many of the same `GPUParticle2D` scene. In my earlier Godot 4 build (v4.0.beta.custom_build [2a04b18d3]) I did not get any errors (but got the occasional artifact as was my original issue in #69669).

I suspect the PR #70418 solved the artifact, but possibly introduced new bugs. However, I have not specifically built Godot with, and without the PR in question.

I believe this is the start and end of the errors - after which they repeat.
![wall_of_errors](https://user-images.githubusercontent.com/10490534/209046500-9813150c-d6e4-4a11-8e62-79d370d07009.png)

### Steps to reproduce

- Create a GPUParticle2D scene
- Instantiate the scene several times
- Observe the debugger get flooded with errors

### Minimal reproduction project

This project only instantiates default GPUParticle2D scenes with a default particle material.
[GPU_Particle_Creation_Bug.zip](https://github.com/godotengine/godot/files/10283416/GPU_Particle_Creation_Bug.zip)

ERR_FAIL_INDEX(p_id, (RendererRD::ForwardID)forward_id_allocators[p_type].allocations.size());
	forward_id_allocators[p_type].allocations[p_id] = false;
}
void RenderForwardMobile::ForwardIDStorageMobile::map_forward_id(RendererRD::ForwardIDType p_type, RendererRD::ForwardID p_id, uint32_t p_index) {
	forward_id_allocators[p_type].map[p_id] = p_index;
}
void RenderForwardMobile::ForwardIDStorageMobile::fill_push_constant_instance_indices(GeometryInstanceForwardMobile::PushConstant *p_push_constant, uint32_t &spec_constants, const GeometryInstanceForwardMobile *p_instance) {
	
	p_push_constant->omni_lights[0] = 0xFFFFFFFF;
	p_push_constant->omni_lights[1] = 0xFFFFFFFF;
	p_push_constant->spot_lights[0] = 0xFFFFFFFF;
	p_push_constant->spot_lights[1] = 0xFFFFFFFF;
	p_push_constant->decals[0] = 0xFFFFFFFF;
	p_push_constant->decals[1] = 0xFFFFFFFF;
	p_push_constant->reflection_probes[0] = 0xFFFFFFFF;
	p_push_constant->reflection_probes[1] = 0xFFFFFFFF;
	if (p_instance->omni_light_count == 0) {
		spec_constants |= 1 << SPEC_CONSTANT_DISABLE_OMNI_LIGHTS;
	}
	if (p_instance->spot_light_count == 0) {
		spec_constants |= 1 << SPEC_CONSTANT_DISABLE_SPOT_LIGHTS;
	}
	if (p_instance->reflection_probe_count == 0) {
		spec_constants |= 1 << SPEC_CONSTANT_DISABLE_REFLECTION_PROBES;
	}
	if (p_instance->decals_count == 0) {
		spec_constants |= 1 << SPEC_CONSTANT_DISABLE_DECALS;