### Godot version

4.0.beta10.official [d0398f62f]

### System information

Windows 10, Vulkan, NVIDIA GeForce RTX 2060m (31.0.15.2698)

### Issue description

I'm getting some kind of clustering/blocky artifact when using spotlights, with no fog or any fancy rendering stuff whatsoever.
I've looked through a bunch of similar issues, but the only ones I could find were related to volumetric fog or other environment effects that I am not using.
Not sure if I'm just missing something, but I think I've played with every option in the spotlight and every option in a WorldEnvironment and nothing makes it go away.

The only lead I have is that the intensity of the artifact seems to be affected by the spot angle. It cycles in a sawtooth pattern every ~0.07 degrees.

![image](https://user-images.githubusercontent.com/13819558/209914720-77a637ea-8cc7-4cff-8216-363f9150885a.png)

Lmk if you need more info or need me to try anything.

### Steps to reproduce

1. New Project (Forward+)
2. Put down some MeshInstance3Ds as a backdrop
3. Put a SpotLight3D
4. Raise spotlight intensity, lower spot angle, and increase range to see it better
5. Slowly increase spot angle to see cycling effect

### Minimal reproduction project

[testspotlight.zip](https://github.com/godotengine/godot/files/10318069/testspotlight.zip)

#ifndef CLUSTER_BUILDER_RD_H
#define CLUSTER_BUILDER_RD_H
#include "servers/rendering/renderer_rd/shaders/cluster_debug.glsl.gen.h"
#include "servers/rendering/renderer_rd/shaders/cluster_render.glsl.gen.h"
#include "servers/rendering/renderer_rd/shaders/cluster_store.glsl.gen.h"
#include "servers/rendering/renderer_rd/storage_rd/material_storage.h"
class ClusterBuilderSharedDataRD {
	friend class ClusterBuilderRD;
	RID sphere_vertex_buffer;
	RID sphere_vertex_array;
	RID sphere_index_buffer;
	RID sphere_index_array;
	float sphere_overfit = 0.0; 
	RID cone_vertex_buffer;
	RID cone_vertex_array;
	RID cone_index_buffer;
	RID cone_index_array;
	float cone_overfit = 0.0; 
	RID box_vertex_buffer;
	RID box_vertex_array;
	RID box_index_buffer;
	RID box_index_array;
	enum Divisor {