### 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)

framebuffer = RD::get_singleton()->framebuffer_create_empty(p_screen_size / div_value, RD::TEXTURE_SAMPLES_4);
	} else {
		framebuffer = RD::get_singleton()->framebuffer_create_empty(p_screen_size / div_value);
	}
	{
		Vector<RD::Uniform> uniforms;
		{
			RD::Uniform u;
			u.uniform_type = RD::UNIFORM_TYPE_UNIFORM_BUFFER;
			u.binding = 1;
			u.append_id(state_uniform);
			uniforms.push_back(u);
		}
		{
			RD::Uniform u;
			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
			u.binding = 2;
			u.append_id(element_buffer);
			uniforms.push_back(u);
		}
		{
			RD::Uniform u;
			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
			u.binding = 3;
			u.append_id(cluster_render_buffer);
			uniforms.push_back(u);
		}
		cluster_render_uniform_set = RD::get_singleton()->uniform_set_create(uniforms, shared->cluster_render.shader, 0);
	}
	{