### 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)

Divisor divisor = DIVISOR_4;
	Size2i screen_size;
	Size2i cluster_screen_size;
	RID framebuffer;
	RID cluster_render_buffer; 
	RID cluster_buffer; 
	RID element_buffer; 
	uint32_t cluster_render_buffer_size = 0;
	uint32_t cluster_buffer_size = 0;
	RID cluster_render_uniform_set;
	RID cluster_store_uniform_set;
	
	void _clear();
	struct StateUniform {
		float projection[16];
		float inv_z_far;
		uint32_t screen_to_clusters_shift; 
		uint32_t cluster_screen_width; 
		uint32_t cluster_data_size; 
		uint32_t cluster_depth_offset;
		uint32_t pad0;
		uint32_t pad1;
		uint32_t pad2;
	};
	RID state_uniform;
	RID debug_uniform_set;
public:
	void setup(Size2i p_screen_size, uint32_t p_max_elements, RID p_depth_buffer, RID p_depth_buffer_sampler, RID p_color_buffer);
	void begin(const Transform3D &p_view_transform, const Projection &p_cam_projection, bool p_flip_y);
	_FORCE_INLINE_ void add_light(LightType p_type, const Transform3D &p_transform, float p_radius, float p_spot_aperture) {